I already know I'm not been unreasonable but need to vent. This girl (let's call her Sarah) used to work for me, was the sweetest girl, a really good friend. My brother lived far away with his very long time gf. Sarah's bf was a dick, really controlling bla bla bla... Sarah (with a lot of hand holding and crying at work etc) managed to leave him. Said ex looks a lot like my brother. Fast forward 3 weeks. My brother has left his gf of 12 years. 2 weeks later Sarah and brother are together and she's working for him (ok I can deal with that, things happen).
My issue is, she's now a complete bitch to me. I've always supported her when really I didn't have to remotely get involved. She's in a family WhatsApp chat and just ignores it. I lent her something of value a few weeks ago, asked her to bring it last Sunday to family dinner and she forgot it. I need it for Sunday and she's still not dropped it off. And whenever I message her she's so short and arsey.
She's the same with my mum. It's like she's with my brother now, moved in etc she doesn't need to make an effort.
Should I take it personally or is she just not really a nice person? I can't get my head around it.