I'm so sorry you guys are going through this.
My dad died when I was 12, and I had 2 older teen siblings too. The worst thing my mum did was kinda... vanish. Like she was still there, but not really there. I don't know if it was grief or if it was her parenting style though. Not only did she never talk about him, or our grief, she just didn't parent us any more. No encouragement for school work, no congrats on great grades (for me), or the failing grades (my siblings). No outings, holidays, doing stuff at home, nothing.
No staying in touch with dad's family (all organised by them, or by me when I was older).
Never been offered to visit dad's grave. The first time I did that was a few years ago with his family, when his mum died.
Like PP's, I have no photos either. I have one photo of him holding me as a baby. I'm certain there would be more somewhere, but my mother has certainly never offered me any.
The funeral was a weird, weird day for me. I was still in shock, denial even. And I get that my mum was grieving, but I did not spend the morning at home. I was sent to a friend's house. Friends mum even had to buy me an outfit for the funeral. I went with friend to the funeral. It was weird. Then after the funeral, me and my siblings stood out the front while people lined up to say sorry to us, by ourselves. Don't know where mum was. 🤔 And as a kid who'd never been to a funeral, I was so confused as to why people were apologising to me! Even if mum had just stood with me, would've been something rather than absence.
Anyway I'm sure you won't do that! I guess I'm just venting, as I've never really talked about it.
As far as your question about grieving, I think it's ok to get upset in front of your child, but be open about it and maybe try and turn it into a nice reminiscing session. I don't think you should cover up your grief, your child needs to see that it's ok to be upset.
I'm sure you'll be a great support for your child. Even just asking this question shows that you're putting thought and effort in already. Hugs to you all xx