Has she been in contact with any other bunnies? Could she be pregnant?
Have you been handling any other animals recently. Scent could still be on your hands to make her be aggressive.
Any changes at all around her environment or within the house (new animal, new scent)
If it continues, I would recommend taking her to the vet to see if it is healthy based.
Regarding spaying and neutering. Sarah is right. While, I understand why your mom feels that way, itt is true that you need to have a rabbit-savvy vet do the procedure – due a bunny’s fast heart-rate and the amount of anesthesia that is then needed. But in the last 10 plus years, a LOT more is known about rabbits and there are tons of rabbit-savvy vets. (depending on your location).
Here is a really great article that you can show your mom — https://rabbit.org/faq-spaying-and-neutering/
It’s rather long, but it covers everything — from the benefits, to how to find a rabbit savvy vet, the types of questions to ask, to offer a list of rabbit savvy vets and pre and post surgery advice. I encourage you and your mom to check it out and continue learning more about the spaying and neutering rabbits as so much has changed in the last 20 years.