Is this girl inappropriate or just plain bitter?

I have a female acquaintence who has been acting very quietly resentful towards young parents these days. Whenever she finds out that someone unfriendly to her is pregnant or having a kid soon(which is occuring quite often lately, weird as it is), she mutters under her breath "why are people ok with that jerk having a kid, but they told me to get an abortion when I had a 'scare' a yr ago?" She's hated celebrity Nicole Richie for a long time & when the world found out Nicole Richie was pregnant this summer, this girl hit the roof. "How can that anorexic druggie Nicole deserve a baby, but people told me to get an abortion? How can people say they're happy for her, but nobody supported me?" is what she says. It's getting a bit redundant & annoying. Whenever we made remarks to her like "I can never imagine you raising a kid," she gets mad(but does a fairly good job hiding her anger). Is this normal behavior? Why is she acting like this?