My Protestant family called the “night before” a “Viewing” which means the open casket and a receiving line, but no formal program or service. The funeral was a service conducted by a minister, either in church or at the funeral home, again with open casket. We kids always went so I got used to it but I don’t think we went until we were about 9. And everything was explained to us. We never used the term “wake” - that was, for many years, largely used for Catholic deaths. I think people now tend to spread that term around, although most obituaries for non-Catholic deaths use the term “calling hours”.
My Jewish family, and all Jewish funerals, DO NOT have open caskets, ever. It is customary for friends to go to the funeral home or synagogue early, before the service, to greet the family in a side room beforehand. There is nothing ahead of time - no wake, no viewing, no calling hours. After the service is the burial (rarely cremation, although that is growing a little in popularity - in fact, many Jewish cemeteries will not allow you to inter the ashes, only the body). There are certain prayers at the service (always the 23rd Psalm), plus the eulogy (by the rabbi or by family members, or both), and sometimes there is a cantor to sing certain traditional pieces. At the cemetery, there are other prayers, and the family and any willing attendees participate in putting some dirt in the grave after the casket is lowered. It’s a very moving ritual.
After the burial, there is shiva. By the way, “shiva” comes from the same Hebrew root as “Shabbat” (Sabbath) - in Hebrew, “v” and “b” are variations of the same letter so they are often both used in words of similar meaning. Both words come from the word “sheva” which means “7” - God rested on the 7th day (Sabbath), and there is a 7-day intense mourning period known as “Shiva” (also sometimes called “memorial week”) during which the family does not work, go out, or do anything except receive guests. After the funeral, there is usually a gathering, at a home (not necessarily the mourner’s home if they are not from the area, and occasionally at a restaurant). If it’s at a home, those attending bring food - no one sends flowers to a Jewish funeral or a Jewish house of mourning. (If you want to do something, you make a donation to the synagogue or a charity of importance to the family.) There is often a memorial service conducted by a rabbi or any knowledgeable Jew in the family’s circle, which requires 10 Jewish adults to be official. Anyone can attend this. Usually that is announced in the obituary or by the funeral director. So, if “shiva” is from 3-8, there might be a service at 5:45 - depends on the family, the time of sunset, and other factors. People who want to pay their respects to the family can go at any time during this period, during the announced hours - and bring food. It’s important to know if the family keeps kosher or follows dietary laws, and to what extent.
Because there is no open casket, we started taking our son when he was about 6 or 7 to the funeral, and occasionally to the home. We felt it was important for him to learn to be part of the community and to fulfill his obligations to others. He learned many of the prayers and blessings in Hebrew school, so he could participate in certain parts, and it was important to do that.
We did not take him to anything open casket, because it was not his tradition or within his experience, until he was in 10th grade and a friend’s father died. We took that opportunity to explain this custom and to prepare him for it.
And as for your friend not going to anything - I think she is either incredibly fortunate to never have had a friend lose a parent or a sibling, OR she has not been raised with an understanding of the importance of having people around you at the darkest time in your life. She may not know what’s expected or what will happen, so she avoids things.