Welcome to BB! With bonding questions, knowing the fixed status of all rabbit parties is essential. I assume Marshmallow, only being 8wo is not fixed, but is Bella fixed? There are many issues with two unfixed rabbits being together, a large one being if one is young, the likelihood of the young one being sexed incorrectly (you were told it’s a she, but it’s actually a he) is a fair possibility, leading to a litter very quickly.

Frankly speaking, it was extremely irresponsible for your parent to put them together. It shows a genuine lack of understanding of rabbit bonding. It’s not stupidity, as the large majority of people don’t know how much of a process bonding rabbits is unless they are researching how to properly bonded their rabbits, but being “annoyed” that they are housed separately is not a reason to shove them together. Fights can occur.

They need to stay separated until marshmallow is fixed, and you need to wait one month following so his/her hormones mellow out. If Bella is not fixed, getting her spayed is highly recommended so the bonding is successful, as well as preventing her from developing cancer in later years (highly possible for unspayed females rabbits).

I recommend both you and your parents read the Bonding information provided on the BUNNY INFO section of this website. It outlines the proper steps and prerequisites of the bonding process, which can take months. If your housing situation does not permit the time, space, dedication, etc for bonding marshmallow and Bella properly, rehoming marshmallow may need to be discussed. I only mention this because again, if your parent was annoyed with two cages, I imagine the idea of swapping territory, developing neutral territory, supervised dates, etc. may be seen as superfluous and unnecessary when it isn’t; it’s very necessary. Marshmallow is very young, so his/her hormones are not fully developed. When they do, hormonal behaviors which can cause serious fights can occur in a split second, which is why separation is required.

Other users will be able to chime in with their recommendations and advice as well. Generally, dominance is whatever the rabbits decide after a healthy bond has been established. Size, age, etc.. don’t matter. Currently, this seems very rushed and may create a lot of stress for Bella. Separation is key.

I hope you and your parents find the information in the bunny info section helpful in making sure both marshmallow and Bella are happy and healthy, both separately and together. Feel free to ask any more questions!

I agree with everything Wick said. At this point, it is unlikely that the little one is trying to establish dominance. Bella was chasing Marshmallow because there is a new bunny in her territory. Females are notoriously aggressive about their space. Just putting a new bun in her space was probably startling to her. Marshmallow, being new, was probably scared, which is why she chased back. At 8 weeks old, she can stress very easily, which can create a life threatening illness. She really needs to be allowed to settle without Bella being around. If neither one are fixed, hormones are also at play, and that is a very dangerous combination. Bunnies can and will fight to the death. Right now, the only thoughts on their minds are fight and breed.