Wakes are not a problem for us, but the actual funeral depends on a lot of things. The kids themselves, of course - both of my children understand, and are okay with it, but there are other things, too.
My oldest daughter went to my grandfather's funeral - she was three - no trouble, but then, her daddy went, too, and he was able to help her when she got antsy. I couldn't attend to her, because I was attending to my mom and my grandfather's girlfriend (practically part of the family).
However, if we are going to a funeral of someone we are not particularly close to, I am NOT taking my oldest. She doesn't do well sitting still, at all - she would be miserable, and so would the people sitting around us. At church, she does okay, because we go to contemporary services that have a lot of dancing and music - but funerals don't tend to be quite so rambunctious.
Also, it depends on whether I will be able to attend to the kids. My mother really needed my emotional support that day - she doesn't do well at funerals anyway, and this was her father; and my grandfather's girlfriend was literally leaning on my shoulder. I couldn't carry around DD. Be aware when you go to the funeral - you will be on kid duty, because you husband will be dealing with other things.
I am very sorry to hear of your family's impending loss. Prayers for healing and peace coming your way.