A long time ago I realised one of the reasons I don't like weddings is that it seems everybody is put together in the same room to play "happy families and friends" for a day. Some manage this spectacularly, some not so.
I also come from a very dysfunctional, difficult background, OP, and there's nothing worst than the perfect British wedding to bring out that to the surface, and make me think my life was, has been rubbish compared to those pictures of perfection offered at weddings.
I'm from another culture, you could say much more relaxed than the British - or Americans - about presenting our lives as perfect or as coming out of a fairy tale. One trait that really baffles me about British culture is that not even good friends tell each other about their private lives. So you always see the perfect surface, never the depth of human experience.
That's why forums like these, and people publishing their biographies to the world, gossip in tabloids are so popular in this culture. People are starved for what really goes on in other people's lives, because not even within families, the full picture of reality is openly exposed.
This is just a point of view to show you that you are not seeing the full picture of your friend's life. It might be much more complex than that. You and your husband probably just have a family like most of us, a dysfunctional mess, that we manage to survive the best that we could.
OP, pour yourself a glass of wine and be happy for the life you have, and how far you have gone inspire of all the difficulties. And also raise your glass for your friend and wish her all the best with her life. It will make you feel better.