Maybe you could try multiple harnesses to see what she likes. Harnesses can be very controversial in the bunny world, so make sure you do your research on them before use. Find the best one and see how your bunny reacts.

Could you use a break-away collar, that would easily come undone if caught on something?

Is there a way you can keep a pen so when you walk in your room you have a foot and then you half to walk over it to actually get in your place? then you would only need to collar her when you take her outside? Not to be devious but they won’t know what is going on behind your door and you can share the importance of how dangerous collars are for prey anaimals because as you know, they can get so scared if they get stuck that they can have a heart attack and die.She would probably be in a carrier anyways outside of your place so she wouldn’t need to wear one.

What if you microchip her so she will always have your information in her if she were to get lost or go on a running spree down the hall?

I hope the best for you and you can even send them links that show how dangerous it is for bunnies to have collars and you can even have a vet or two vouch for you!