Yup this is dumb, MC is trauma city so it's fine that she doesn't go say "she's a fucking psycho get her away", but for the others to be like "this person that isn't making our friend/family happy at all is clearly the best thing, lets all hug and invite her into our lives" is just too much, is she fucking god of sociability? Can make everyone love her by just showing up, including a 3year old? I'm not actually angry because I've seen authors do much worse, but this is forcing it, I wonder how many chapters this will drag on.
On a separate note, this "new" girl is gay for MC right? The thing with the husband was to get MC away from him more than her stealing him? Maybe they never even had sex. Possessive obsessive for the MC that is.