Though I'm mostly a silent reader but would like to give my 2 cents on this topic. First thing i'm married and trust me when I say this I share Tom jerry relation with my husband and trust him more than anyone in this world. If I put myself in Anjali's situation I think I would:
1. Trust my husband more. Ask him questions. Ask my brother also for proofs. If not satisfied, i would leave with my husband.
2. Will try to find things, because not everyone can lie.
3. Definitely not meddle in between my brother's and his wife relation. Just because i'm suffering doesn't mean they should also suffer even if my SIL is at wrong.
4. I would want to make my life right. Fight for myself and for truth.
5. Definitely not blame my brother for changing after marriage. Would always wish and want their happiness.
6. Most importantly I will not behave like sick 24*7. And not throw tantrums like a two year old because my fav doll has been snatched.