Yes, these are normal changes related to puberty. She could very well be pregnant. Give her nesting-material so she can build a nest. She wont do that until a day or so before she gives birth. She might become aggressive towards the male if she’s pregnant. You should separate them, because a doe can get pregnant right after giving birth, and that means the second litter will have a hard time surviving because they have to compete for food with the much bigger kits from the first litter. It also puts a huge strain on the mother bunny’s body, of course.

Feed her extra now, alfalfa pellets and alfalfa hay are good supplement for pregnant does.

The Binky Bunny forums doesn’t allow discussions about intentional breeding. Here’s an excerpt from our rules regarding this:

D. Discussions of Breeding and Rabbits as Livestock: Discussions involving intentional breeding (of any animal) and meat & fur rabbits are not allowed.

• Accidental Litters: We are not a site or forum that has the necessary experience to advise you in this matter. It would be better for your bunnies to use reliable resources for pregnant/nursing does and their babies. Here is a list of resources that you may find very helpful:
http://www.bio.miami.edu/hare/surpriselitter.html
http://www.rabbit.org/care/babies.html
http://www.rabbit.org/care/newborn.html
http://www.mybunny.org/info/newborn.htm

-http://www.rabbitsonline.net/ caters to a broader range of experience, may also be of help.
-Be sure to seek vet care and advice.
-Do not use this forum to give or sell bunnies as well.
-Since we don’t allow prolonged discussions regarding this, the thread will be locked.
-We hope you will find the above resources useful. Please feel free to to ask about other aspects of caring for your bunny

(The forum rules can be found here: https://binkybunny.com/FORUM/tabid/54/aft/10084/Default.aspx)

Welcome to BinkyBunny.

As bam said, you need to separate them. And cross your fingers and toes that she’s not pregnant. She’s way too young to give birth and raise a litter. Yes, she’s probably able to conceive, but that doesn’t mean she’s old enough. If she gives birth at this age, there’s a good chance she won’t survive the process, and if she does, it’s likely that she will abandon the litter (or even kill the kits) because she’s too young to know what to do.

You can not keep two intact rabbits together. Their behavior is unpredictable and they are highly territorial. They will end up fighting, and chances are you won’t be there to stop it. One day you’ll come home to injured, or dead, rabbits. You’re already seeing hormonal/territorial behavior, don’t wait until things escalate. Professional breeders don’t leave two rabbits together to get it on, they know it will result in a fight. They are put together for a few minutes, supervised. If they breed, great, if not, oh well. I’m not telling you this so you can do it “right”, but so that you realize that leaving them together like this is highly dangerous. They need to be separated yesterday.

Please, do not breed your rabbits. There are so many in shelters right now, getting euthanized because nobody wants them. Purebreds and “mutts” alike. The only legitimate reason to breed more rabbits is to protect established breeds, just like with dogs or cats. You said yourself, your buns are of unknown make and model. They are mixes, not any different than the ones getting dumped at the pound every single day, and put down. Why would you want to add to that? Please reconsider, separate them, get them fixed and bond them later on if you wish.