Hi there, welcome 🙂

Regardless of your decision to bond, spaying (the term for castrating a female) is important in female rabbits, as they have very high rates of reproductive cancers (about 75% by age 6). She is not too old to be spayed, as long as your vet if experienced with spays. So you will need to call around and find a good vet, and you might need to be prepared to drive a bit.

Regarding bonding, I think most rabbits are happier with a companion. Not all, but it does seem to be very enriching for most rabbits. So I think if you are open to it, that would be wonderful for her. Breed, age, and size do not really matter. It is more about the rabbit’s personalities. It’s ideal to try some dates before committing, but most pairings do eventually work if the bonding process is done properly (a small percentage of bunnies just do NOT like each other though).

In my mind, 5.5 is more middle aged. Almost a senior, but by no means geriatric. She could live to be as old as 12 if she gets spayed. So that’s many more years that could be made even better with a friend.  I actually just supervised a bunny date at the shelter between two bunny ladies that were 5 and 6, and it went very well. 🙂 As a testament to spaying, the 6 year old came into the shelter unspayed. When they did the surgery, they found she had cancer all throughout her uterus, but they think they were able to remove it all and she has been doing great.

My girl, Esther, also had uterine cancer before being spayed. It was quite bad and she likely wouldn’t have lasted long if she hadn’t been spayed when she was 🙁 . She’s around 6 years old. Her surgery went very well and she had no problems after.

I recently started fostering another rabbit in hopes of bonding him with Esther, and we’ve been making progress. She was quite aggressive towards him at first, but with small times of exposure through the pen every day (I have opaque barriers up most of the time because she is nippy) they have already been making good progress. I do think this aggression isn’t due to age, but more so due to her being slightly fearful of him and territorial.

Gotcha! The spaying/neutering situation has been really hard with covid. So many members have been saying they’ve had to wait really long times!

It’s true that females can be a bit more territorial, but it’s hard to gauge how rabbits will be with other rabbits in neutral space. I think inquiring with the shelter about some dates after she’s spayed is a good next step. That will give you a sense as to how she is towards other rabbits outside of her home turf.