Hi Nita, I'm with Wayne on this one. I brought my now 10 month old kitten home much to the disgust of Felix, my fiance's 5 year old (both females). After much hissing we put Tasha in the bathroom and NB!! kept giving Felix more attention than Tasha. We found that letting her know she was still top cat helped a LOT and now she mothers her and they play beautifully.

Good luck, I'm sure everything will go OK.