My (32M) wife (32F) is jealous because her friend (32F) has a new life and a husband. It is impacting our life because it feels like she settled down with me.

My wife and I are together for 11 years. Got married 5 years ago and we have 2 kids (5 and 2). We are both in STEM and we have a good life and we kind of did everything by the book and she was always proud of that.
Her friend Mia (there are 4 of them in the group) was always little different, content on her own and she never took life too seriously. She didn't care what we think, what random acquaintances do... She quit Uni, worked low paying jobs, then got back to Uni... while people around her were getting married and having kids. My wife always thought it must be hard for her, but I personally never got that impression. She could always have any guy she wanted, she always had enough money for day to day life and travel and she always seemed content and easy-going. We tried to hook her up with some of our collegues but she didn't like them. She said she is good on her own and if she is going to get married it will be with someone amazing. (I think her parents had bad marriage so she wasn't much into that)
2 years ago she met great and very handsome guy and they seem happy. My wife didn't really care at first and she was happy and supportive. They got married and they are going strong, living in another country so we don't see them often. A week ago we went on a group holiday (4 couples) and my wife had snarky comment on anything Mia did. Mia is still the same person, she is 'just' much richer now.
She thinks that Mia didn't deserve to meet such a great guy because she had many guys before. That people have to compromise and that she didn't compromise nothing. That she got anything she ever wanted. She even asked me if he cheated when we were on a guys night out...
I'm just confused and don't know how to react. I feel like my wife is unhappy and everything I do isn't good enough. Now she isn't happy with her body. With our life. Food we eat. She is annoyed with bunch of little things. I think she now regrets playing by the book and wishes she did more interesting things in her youth. Dating.mobi, what is going on? Is this normal?
Tl;dr: after a holidays with our friend my wife became unhappy with our life.


Source.

What is STEM?

So your wife is jealous that her once poor average friend is now doing good and rich and happy? What a total bitoch! Terrible friend

Found out it's Science, Technology, Engineering, Mathmatics...as in that's what the couple is employed as I guess...so a cpl of nerds...which explains the lack of real life experience and turning to an online forum for advice.
I'd go with Stupid, enTilted, Ego maniac, Morons

Your wife is hater