Should we move?

I didn't say it was controversial. In my 1st post, I simply said she may not want to speak italian
I also asked if you'd considered a number of things related to moving. You have ignored those questions, misinterpreted what i said about language, and merely accused me of something else.
Unless she was born in italy, she is english, so your point about children speaking THEIR language is disingenuous

Wow, that's quite fundamentalist; no choice about language, culture, religion or hobbies...
You will be the children/grandchildren WE want you to be and who fits into a society that makes you do stuff you don't necessarily want to do...

If I was your SIL or GD I’d be very unhappy with my MIL/GM posting so much of my personal business online……maybe they don’t want the whole of Brighton knowing their life stories before they’ve even unpacked. Just think this through OP.

I'd perhaps rent an Airbnb in the off season so perhaps look at October half term. The coast is a much different prospect when it's blowing a gale and horizontal wind in the autumn/winter. You can see if it's somewhere you'd want to live for a few years then. I think your son would come round it's quite easy Brighton to London on the train so you could still visit them often.

In regards to your son, did he know that you were originally planning Italy? Brighton is much closer and he will be able to holiday there with his children during the school holidays so you won't be too far for him.

If it helps at all, my much-loved GM ended up with one DGC across the Atlantic (through a company move for his father; my cousin is still over there in his 70s) and DB and me in the UK. We were always very close to her and she did quite a lot of care for DB and me (DM was a single parent); At one point we even lived together as she grew older but I don’t think it adversely affected her relationship with
my cousin.

This! Was about to say something similar. Stay in London and visit Brighton every week for an overnight. Make it the same night. Make it every week. I did this to successfully repair a fractured relationship with my mother starting about 10 yrs ago. I know this isnt quite the same however the week rolls round very quickly and the consistency is key. Say you travel down every Thursday pick your lovely girl up from school. Cook dinner together ( in italian!) Hang out. The everyday stuff. That way you provide a fixed point in the week for your SIL and Darling GD. He didn't plan this move expecting you to follow so don't. Don't forget your grandaughter can come to london to see her cousins etc at weekends and holidays and vice versa.
You sound so loving and lovely. You are honouring and remembering your darling daughter so meaningfully by ensuring her daughter stays close to her maternal heritage.
It's lucky that SIL is only going to Brighton not his country of birth. This can be worked with.

And if your GD decides that she hates tennis or would prefer another hobby to piano? Feel rather sorry for thus girl......

I'd wait OP until the decision is clearer. See what the new situation looks like when they move. The impact on DGC, how you feel. There's no rush and if you have doubts about a big decision that's not time sensitive, the best advice is usually to do nothing until the doubts subside. There's no right answer. Both choices are valid and reasonable, so its a heart decision. Wait until you know what you want.

I am so sorry for your loss. How does your granddaughter feel about her and her dad moving to Brighton? Is she happy and excited by it all? This is a big decision for you and understandably weighing on your mind, but I really don't think you should rush into making a decision right now. Let them go with the understanding that you may or may not one day move too, but try to keep an open mind. First see how things transpire after they have moved. It could be very lovely visiting Brighton at weekends and holidays, and vice versa your granddaughter coming to visit you in London. You could build some amazing memories with these special visits. It is really not far away on the train. Let them go for now, keep an open mind for a while, and see how it acts out. Everyone's feelings may evolve once they have actually made the move. You will always be there for your granddaughter, she knows that, I would say just let the situation evolve a little before jumping to any decision.

Brighton is a horrid place, why would love it?

You sound wonderful grandparents.

This is good and right on so many levels.

Your son will surely understand, and London is not at all far away (in my book) and you can still see your other grandchildren a lot in Brighton which they would no doubt love.

I think you should definitely go to Brighton.

From your post I would say move to Brighton, your granddaughter is an age where having you around will be great for her and will ease pressure on your son in law. Yes he might meet someone else or decide to move again, but life is full of uncertainty. Get somewhere with space for other family members to stay (for teens a weekend in Brighton will be great). You may want to reevaluate in a few years time, when there is less need for emotional and practical support. Your heart definitely doesn’t sound like it’s in London anymore.

I am very sorry for your loss.

You put forward a very strong case as to why you should move. It also sounds as though that is what your heart wants to do. Hopefully your son will eventually see it from your point of view. I mean, if you went back to Italy as planned, you would presumably see him and his kids less than if you move to Brighton.

This may be a grand arrangement, but have you considered, and this will sound harsh, what your position will be if he meets someone else?
Brighton is a cold, winndy boring place with an uncomfortable stone beach, and if you aren't arty/crafty, you are a social pariah ( i may be exaggerating, but it's no London, and certainly not Italy). Would you both be happy there, especially when your GD gets olders, starts making her own friends/social life, and no longer needs you in her life so much.
Appreciate your thoughts on keeping her Italian culture, but this may not appeal to her; you are very much projecting what you want here...
I would not recommend...

One thing to consider is ( depending on your age and health) who would look after you if you moved to Brighton and suddenly needed help for some reason. It doesn’t sound as if your son-in-law would have capacity for this or would feel you were his responsibility. Short term the idea of renting in Brighton to see if it would be a good move seems like a good idea.

In your situation I would move.

You want to downsize anyway, you fancy living by the sea, and it's not like you're moving to the other side of the country - you're within easy reach of the rest of your family.

I understand why you would want to move, and appreciate that your son in law has said he’d be happy for you to move with them. However, how will you feel if he starts moving on, with any possible new relationship? Sometimes these things happen really quickly, and he might not be so happy then for you to have such close involvement in their day to day lives.

Brighton really isn’t that far. I’d stay in London.

I'm very sorry you lost your daughter @Piovereacatinelle

I know someone in your situation who lost their daughter soon after she had their first grandchild. When their son in law decided he wanted to move, they followed (with his blessing) only for their son-in-law to then decide to move again, further this time, about 4 years later to a place that they couldn't/didn't want to move to - the other side of the country. They had uprooted their whole lives to be there for their grandchild after their daughter died. They have a good relationship with their SIL but are now faced with moving again back to where they were before or staying without a grandchild there, and a massive wave of grief has come back as it feels like yet another loss.

If it were me, especially having seen a friend go through it, I'd probably either do one of three things

1. Rent out your London home and rent a place in Brighton for a year minimum to see if it's really a good move for you. Is it what you expect or are you tagging onto someone else's life? Does your granddaughter need you in the same way? Or have things improved and now they need you only as a grandparent and not caregiving etc. and they are ready for a fresh start - still with you in their lives, but in a way that's more like it would be had they not gone through the loss they have.
2. Keep a small place in London so you can spend time with your other grandchildren and adult DC and not have resentment from them you left for another grandchild, and have a place in Brighton. Maybe a 2 bed place in Brighton so they can visit and a 1 bed in London. Try to be in London a couple long weekends a month to see family etc.
3. Stay in your home for at least a year after they move and see what it's like. Visit, reassure yourself and don't act too hastily.

Your granddaughter is a connection to your daughter so it makes absolute sense you want to be with her and that maybe it feels harder to not be with her than your adult DC and their children. I wonder if you need to be as geographically close to keep that connection, or if maybe with time and reassurance, you have built a solid foundation for your relationship and they can move onto a new chapter with your love and support from London.

Best wishes to you

Yes agreed. Your granddaughter is the one who needs you the most, she’s lost her mum.

Brighton is close to London, just a short train ride away.

You sound lovely .. whatever you decide your thought and care shows that you will always put family first .. perhaps book a holiday down to Brighton and stay in and air bnb or cottage and see what you think of it ?

If I were you I would move. I’m so sorry for your loss.