Would I be wrong to do it anyways?

I just moved out of my moms house about a couple weeks ago and when I moved out of her house I planned on rescuing a cat I’ve wanted a cat for years like Atleast like 7 years I’ve been counting the days lol till I moved out. Well I told my mom I was getting a cat and she was like no, then I can’t come over all this she kinda made it all about her. Which I find kinda annoying bc if she comes over I’ll put the cat away clean up a little and everything. She says she’s allergic but she would go to my dads house and he had a cat there idk and wouldn’t show any reaction but i feel it’s my house and I should decide if I want a cat or not and it’s my decision if I get one. She comes over maybe 1 every 1-2 weeks. Would I be wrong to just go ahead and adopt one anyways?