I've recently got a new job, new boyfriend and new flat and she now gives me one word answers. She's also 43 and acting very childish
Why would a family member stop talking to me when things are going well in my life?

I've recently got a new job, new boyfriend and new flat and she now gives me one word answers. She's also 43 and acting very childish
She might be jealous or just have her own thing going on. It's super easy to forget this (I know I'm guilty of forgetting this), but other people have entire lives that have nothing to do with you. And sometimes, that person is so wrapped up in what they have going on, that your life is an after thought.
It would seem that she's envious your world is looking up and hers is stagnant or going down, and she begrudges you your success. Why she does is a good question.
Childish reactions are their insecurities. Don’t ever take that personally.
Opinion
2Opinion
She may feel threatened by your personal success at the moment.
Maybe out of jealousy or insecurity.
Jealousy.
Normally jealously
Jealousy?
Superb Opinion