It does sound like she’s marking. If you’ve had a BF or a friend visit and go in your bedroom, she may be making sure they know it’s HER room and you are HER slave. If she’s going to be in that room regularly, then I would put a second litter pan in a convenient place on the floor, and the second you see her lift her tail or start to wiggle scoop her up and place her in the new pan. You can praise her when she goes in there herself, and say a firm NO when she starts to pee on the bed. The praise for going in the litter pan instead can be followed by a small treat, so she learns that it’s good to go there, even if it isn’t her main litter pan, and not rewarding to mess the bed. If you don’t catch her in time, place her in the pan anyway, blot the pee with a paper towel and place it in the litter pan, and toss all poos into the pan as soon as she makes them, too. You want to train her to use an outside-the-habitat pan and one inside. Some bunnies don’t make it all the way back home when they are out and need to go.