Me personally, I don't like to share every nitty gritty detail about my life on FB. I don't have a huge amount of friends on there, but some of them are more of acquantices then they are real friends. That's just how it goes sometimes on FB though. If you want to be connected you friend the person, but sometimes they just sit there as a friend and you never talk again. Or you friend them and life happens and you don't ever really get to be more then internet friends. Others in my list are people I once hung out with and was great friends with at one time or another until life happened and one of us moved. That's the usual reason my friends list may be bigger then I even feel necessary because I want to stay connected with them even if we hardly talk now.
It's nice to be able to see how our kids are growing and sort of stay connected with family. I'm just not one to post everything on my FB I only post occasional updates, but usually just lots of pics. The updates I do post aren't usually very personal in detail with the exception of big announcements like new babies or an upcoming move. I'm sure I posted when my oldest broke her arm, but that's something everyone would have seen in a picture eventually.
To me I don't like to use FB to air my dirty laundry though. There's just something about posting all the downsides and the drama that I don't get! I don't feel as though my life has much drama but even if it did I don't want everyone I know to read about it either. I like to keep some things to myself because it's not like people normally start a conversation with "hey guess what kind of crap happened to me." Usually it's "hey how are you, good, good so what have you been up to." Or something to that affect I'd think. This could all just be me, but I like to keep my private life pretty private and don't tend to complain about my husband to people, now occasionally I'll complain about the kids and their antics but that's a whole other story ;) I seriously had a friend realize one day that I'd never said a bad thing about my husband while she'd be complaining about hers for a few minutes. It's not that he's perfect but I chose to not complain about it.
I'm sure everyone has their own opinion on this and that's just fine, but this is how I feel about the topic and thought I'd share one honest moms opinion!