I think you should wait until Thumper is spayed and talk to your mom in the meantime. Thumper would also have to wait a month until she heals up and is less hormonal too. You could tell your mom that it wouldn’t be too expensive to add another bunny to the family. It’s just a little more hay, pellets, and veggies. My mom had to deal with it when I came back for winter break with an extra bunny.

Definitely wait until she is spayed and healed up, and all hormones gone. A hormonal bunny isn’t fun to introduce around

My mom didn’t say much. The last time when I got a hamster without telling her, she screamed and screamed at me. I think she’s trying to avoid that now, so she was just like, “Oh, you have another rabbit? He doesn’t seem as smart as Lago.”

I would strongly suggest getting your mom’s approval first. Bring up the good benefits of your bunny having a friend

You would need to get another cage for the second bunny to keep them seperated until they are bonded.

My mom only reacted that way because she knew that if she made a fuss, it would just make things terrible. When I got the hamster, I had just started college and wanted to bring it home for break. She said absolutely not and that I would have to give her back (it started a huge fight that was horrible and I was being immature and told her I wouldn’t come back home for thanksgiving if I couldn’t bring my hamster with me). My parents think that pets are horribly dirty and belong outside. I completely disagree with them. They know what I’m like with animals now and know that I’m extremely stubborn so they’ve learned to deal with having the bunnies home with me on holidays.

Anyways, you should ask your mom before getting Thumper a buddy if you’re living with her. 

Definitely wait until after Thumper is spayed and has had time to heal for a month. At that time, after you get permission from your mother, find out about having Thumper bunny date at the rescue. Just because YOU like a bunny, does not mean she will. And if the bunny you are looking at is a female (you said ‘spayed’ so I assume it’s a girl), please understand that two females can be very, very difficult to bond. In some cases, they do not bond and must be kept separate permanently. This is another reason why taking your time and allowing Thumper to meet different buns and pick out HER favorite is so important.

If you are a minor, your mother is ultimately responsible for any and all animals. If you adopt a new bun, you cannot sign the paperwork, your mother must take possession of the bunny. If you are over 18 but living in your mother’s home and receiving financial support, do not bring a new rabbit into the house without first discussing this with her. It is not respectful and all animals should be a joint family decision as they affect everyone.

Girls can be much much much more territorial, and can really hate other females that try to get into their space

The easiest bonds are typically male and female. If they will let you take your bun to meet the bunnies, that will make bonding much smoother. I would start by trying her with neutered boys.