I'm so sorry to hear that your Mom is so against you having another kitty, but have you told her the benefits of having a compainion for your other kitty.
How when they are alone, they keep each other company and how much more than thrive with having a playmate. How, two, two heads are better than one. Okay, i'm grasping at straws here.
Maybe if you show her what others have posted?
Anyway, I hope in the long run your Mom has a change of heart.

Come on Mom, you know you WANT it.