You've got remember that a big part of facebook is a competition of people trying to make out they have the best life. Its basically public gloating.
She is also probably liking this stuff about 'life is to short' because it fits with her coping mechanism. I accept that I'm probably mind reading on your behalf but I would say when kids are involved the person who doesn't want to work at it is either completely heartless or will be looking for ways to justify things to them self
I'm sure someone who knows a lot more about this stuff than I do would say to not worry about what she is doing, do what you need to do to make you happy.
Don't get me wrong its really (censored) hard - I'm struggling that my W seems to be going out and getting blind drunk once a week and that her mates are trying to fix her up with other men. Made worse by the fact that I've been trying to get her to go out and enjoy herself for the last couple if years but she always had an excuse. I figure its about proving to herself that I'm the problem making what she is doing easier for her. But still all that dwelling on that does is feed my insecurities and make me less attractive (I'm less good at hiding this than I thought I was).
So back to the point - work on your own GAL'g and do things that make you happy.
Both mid 30s, 2 young kids BD 7sep14 XW moved on long ago, now living with OM1 D paperwork in progress