Hellobee Boards

@snowjewelz: I don't know if this will be helpful at all. Without a recent death, for some random reason, my 3 year old started asking a lot of questions about death so I did some reading and talked to our pediatrician who is a friend.
We decided to answer her questions honestly "yes, someday you will die too, but usually epeople don't die until they are much much older," etc. We also talked about death as the end of a book, and how we enjoy the story even though we know it has to end eventually.
For specific loss, photos and a ceremony of some kind (maybe not they actual funeral but something smaller for the toddler specifically) are helpful. Little kids are really concrete.
Basically the best advice I got was to be as honest as you can. Acknowledge feelings (yours and hers), and make space for them.
As adults we are often really uncomfortable with death, and so we experience anxiety talking about it. A friend of mine said "it's a part of life, and you don't really struggle to talk about birth with her, so try to remove your feelings and anxieties from the conversation."
Obviously if your friends mom is dying she is going to be grieving tremendously, and she will need to explain that to.

Again, don't know if it will be helpful, but just some random thoughts.

Eta: I don't believe in any sort of life after death, and am not religious, and so I chose not to go down the path of heaven, etc. when she asked questions.

This website is helpful and talks about how to approach based on age/level of development.

https://childdevelopmentinfo.com/how-to-be-a-parent/communication/talk-to-kids-death/

@snowjewelz: I was extremely impressed with lo. But everyone handles it differently. She really took on a comforter role and wanted to be apart of things. She would sit with my grandfather for long periods of time and rest with him or rub his hands. I worried a few times about her taking on too much but she was pretty adamant about needing to sit with him and she'd get up whenever she felt like it. She was only 4 so I downloaded movies to my iPad and bought new coloring books and quiet stuff to do inside. But we also got them out of the house to run around a bunch and did a few fun activities over the weekend.

@snowjewelz: I think you're right on about children being more affected by the sadness of the adults around them. We lost our family dog in a sudden accident and it was pretty traumatic for me. It was hard to explain to our almost 3 year old why I was so sad all the time. We kept it simple, but honest "Cooley dog died, which means we won't see him anymore and that makes me feel very sad because I'll miss him." It's really tough, but I read that the most important thing is to not gloss it over or pretend like things are all okay because then children are just confused and scared.

Last summer my FIL died, and we had a 3.5 year old and a 5.5 year old. I happened to listen to a This American Life episode that featured a children's grief centre in Utah called The Sharing Place that really helped me. What the kids who seek their support deal with is far more catastrophic than what we were facing, but the ideas about how children face death and grief was really interesting.
This is the centre:
http://www.thesharingplace.org/

This is the podcast:
http://www.thisamericanlife.org/radio-archives/episode/557/birds-bees?act=3#play

I would say that the description from them about the delay in experiencing grief has been what we have seen, though mostly from my now 6 year old.

My heart goes out to your friend, losing a family member is so hard for everyone...<3