Hi, yes its normal
I just got molly last week, and had to introduce her to my other 3, the first few days none of them liked her, exp, karleigh my other girl, but now a week later and they play quite good together, and karleigh is 3
they do get a bit rough with her at times but i guess thats how they adjust, it will get better, molly is a stinker
she really cracks me up though.