Was I right to leave?

Yes of course the OP is allowed a life and she has drawn a clear line in the sand about where her boundaries are. It is her right to do so

but it is also her daughters right to feel hurt and upset that when she asked for her mothers help and support she said no

we can only gatekeep our own boundaries and responses - here the OP wants both to have that boundary but also have her daughter not be upset and that isn’t fair

any choice comes with consequences and this one has - her daughter is allowed to feel upset about it and work through how she feels just as much as the OP was to make that choice in th first place

She asked her to stay and help because the baby was obviously extremely poorly to be hospitalised. I'm sure if the baby hadn't been so I'll, the mother wouldn't be so exhausted.

It takes alot to reach out and ask for help. I think personally I would have stayed and I know my mother would have stayed.

Obviously the OP can prioritise whatever she wants but I can completely understand her daughters upset.

You were already doing her a favour, and were well within your rights to say no to more. Yanbu.

You stayed to help for several days but she still wanted more and is now guilt tripping you. She is finding it hard having two kids and probably nothing you do will be enough for her. You could offer to come and help again soon, but you should not feel guilty for going to the christening. Your life is important too.

I think it’s good you kept your commitment to your friend, a christening is important too.

Your dd needs to realise that you have a life beyond ‘mum’ and ‘grandmother’.

You helped her a lot, her DH needs to step up.

I would have stayed. They asked for help.

I mean it says a lot about you and your relationship that when your daughter said she needed you and understandably needed her mother you left

it is perfectly within your right to do so you had plans you made a choice to stick with the agreement to go to a christening

However your daughter has every right to feel hurt and abandoned and have it affect your relationship with her

Not unreasonable at all. There are two parents there, it’s their job to get on with it.

Personally I would have stayed.

An ill child and shattered parents should take priority over a friend's grandchild being christened

I think it was fine for them to ask and fine for you to say no. The babies dad should be taking a day off to help out if needed since the baby has just been discharged from hospital.

Was the baby out of hospital? if not then YABU as that’s one the most stressful experiences. Presumably her DH would have been with the older child and see would have needed someone to give her a break at the hospital, bring supplies and support her. If the baby had been out of a few days then that’s a bit different as presumably she was tired but she and her DH could have tag teamed to give the other a rest. I think staying would have been the right thing to do unless the baby was quite recovered. I’d the bag was now fine then I would also have left.

When is the christening of your friend's granddaughter? Could you have stayed an extra day or two to do both? (I would have stayed as long as I could and forego the christening, but we all have different priorities.)

Difficult as you had plans already. What has son in law been doing, surely he should be helping?

Of course you didn't have to stay, but I can imagine how desperate your daughter was for sleep. The fact you put a friend's granddaughter's christening above helping your own family has probably upset her quite a bit. I think I'd be gutted if my mum didn't stay to help me when my kid was in hospital because she wanted to go to another kid's christening that she's not even related to. Equally, your DD has a DH (although I assume he's caring for their older child while your DD is at the hospital?) and lots of people have to muddle through with no support.

Difficult one as you had plans for the weekend that you clearly want to stick to but I know I would have stayed to help my DD; especially with the baby being so poorly.

But where is her DH/children's Dad?