Welcome to BB! In my opinion, the best way to introduce dogs is to do it one at a time on-leash. I would probably keep the bunny in a cage or pen for the first few meetings too, because you don’t want her coming right up to a dog that’s not ready to meet her. Keep the dog far enough away from the bunny that it can remain calm and praise and give the dog treats as long as it’s being calm. Speak soothingly and try to keep a really calm environment. Gradually move your dog closer to the bunny cage until your dog is totally calm – no whining, lunging, barking, etc even right next to the bunny cage. At this point you can probably let the bun out, but keep the dog on a leash and keep prasiing the dog for being calm.
Some dogs might go right through this training in a few days and some dogs might never get it; it really depends on the dog’s personality and prety drive. Even if the dog can never be off leash with the bun, this training should keep them from getting over excited and scaring her.
As far as the bun’s age, as long as she’s settled in I don’t see any problem with starting the training. Since you’ll make sure the dog is always calm by keeping him far enough away from the bun, it hopefully won’t stress her out too much. The problem would arise by moving too fast with the dog and letting it get excited, which could scare the bunny.