Hello,
I am sorry about your situation OP but you are obviously very thoughtful.
I lost my father at 19 and my younger sister was 16. We have older siblings too.
My situation is not relevant to yours but I will state it anyway.
Best bit of advice was from a GP - I got outbreaks of awful illnesses after my father died and I remember him saying that grief:
- can hit you hard and really affect your body,
- Give yourself a couple of years to get through it, and
- play the long game and don't worry if you have days that you just can't seem to cope with they will pass but they may come and go over a long time frame.
That was really helpful to see grief as a long term thing if that makes sense?
We had been left money in our fathers will but my mother successfully challenged the will so she got everything.
Looking back, I just can't believe how naive we were but we were young and not specialists in Estate Management.
We were completely screwed out of our inheritance.
The judge at the family court said something along the lines of "don't worry you will get your inheritance eventually from your father's estate when your mum dies one day" or maybe a solicitor said that - but that was the narrative, the narrative was also that my Mum hadn't been looked after and she obviously felt she needed every cent of my father's inheritance.
My mum played that she was a caring Mum and it was believed and we were not really up for challenging this narrative when we were still grieving the loss of our dad, and were honestly concerned as to how we would eat and I probably hadn't even realised just how abusive she was.
Perhaps it wasn't the judge but something along those lines above from someone?
My sister and I were awarded some paltry amount that was not even one year of university fees. ( we were outside the UK)...
My poor younger sister basically had to beg the solicitor for any money from the trust account for her it was really pathetic for example it could go on a text book but not food, in today's terms it would have been around £ 6 k. I know she found the process of asking for any funds really distressing. I remember speaking to her about this while we were eating fucking pot noodles for dinner.
One of my part time jobs involved catering so thankfully I had a source of food in left overs as one of the cooks knew my situation wasn't quite right so I always had one good meal a day because of her.
My father worked very hard and before he died I remember him sitting me down and saying don't worry you will have enough money to keep paying for university etc you are provided for.
The reality is that we were kicked out of home and left to self fund everything. She didn't even buy any groceries after he died and yes my younger sister had just turned 16.
I am extremely proud now looking back at how we both got on with life and got our education (I was already working part time and at university) while almost working full time. Also we were such nice kids we were still kind to our mother but obviously as an adults we had next to nothing to do with her.
It also gave me insight into real poverty and how very quickly your circumstances can change.
My sister had to house share and she actually got raped and I think that wouldn't have happened if she had had better more secure accommodation. I also can't believe re my younger sister how no other adults clicked as to her situation (that includes teachers and part time employers, and even wider family members). There was no pick up or awareness from social services.
My Dad came from a loving family but uncles and aunties were busy with their lives and I just don't think anyone could have guessed as to my mum's scheming.
I don't have much to do with my family now at all.
So what I would say is make sure your wills and guardians and estate is really up to date as to what you want to do.
I would also say give your children money when you are alive rather that it always being due to inheritance (you can make it vest later if you are worried they will blow it).
I would also say photos for each child are important.
I have my own family now and I do just really want to make sure I live until they are 18. I have a somewhat irrational fear of them being plunged into poverty but I don't share that with them. 

When my mother did die (quite recently) well she didn't leave us a thing.
I am incredibly proud of my sister and I. Even though we are not close so much now.
We have never screwed anyone over.
We both got our education.
We chuckle at it now because we can.
I still have one expensive loan from my university to pay off but I own a home and have a loving family.
My youngest sister has done really well financially.
I have very happy relationships and I am most proud of the fact that my sister and I are not bitter. I am kind and generous.
I really don't take anything for granted.
For example, if I go to a restaurant or a movie or a show then I really still pinch myself in the inside as it is such a wonderful treat as I remember just working growing up and working like crazy.
I also think it makes me seek out those who are going through poverty, so if I see a family struggling I will skip them some money. I just know it would have helped me so much when I was struggling so I try help others.