Friend wants me to back down...?

no i dont think you are over reacting. im team peas and carrots! i didnt like the way she approached you, she acted like you were trying to hijack he step kids. her approach wasnt the best but you have to stop and think that your friend is probably feeling insecure with the situation. shes probably wondering does she stack up. will they accept her. she probably got threatened seeing him open up to you before her, maybe its not so easy for her to bond and she was threatened seeing your comfort in the situation? there are a lot of different reasons why she could have acted like that but i dont think any of them have to do w u. i believe it has to do with her insecurities. i think u should let her know you got offended by her comments, they were a bit bit*hy and try to put it to rest. if she has been a long solid friend then some times you have to get through these road bumps. if she seems like a friend who acts out toward you like this more than you would like then id say she probably isnt a friend worth keeping. overall i would say dont let her drama and negativity drain you or bring you down. good luck!