When I was fostering a former outside cat I let him and my bunny be in the same room BUT there was a gate/x-pen type thing separating them. This is a good way to determine how your cat would act if they were all together without anything between them. In my case, the cat would look over at the bun every now and then but otherwise ignored him. He never stared or watched intently for long periods of time. Eventually I let them out together and when the bun ran up to the cat, the cat would sniff him a little but then walk/run away. All of these things… the slight glances but no staring, running/walking away, and ignoring/disinterest, are all good signs to look out for. Your cat might even see them as prey at first, but if you keep them in the same area for a few months she might get used to them and see them more as housemates. There is hope. Although I still wouldn’t keep them out together while you’re not home even if they got along.