Trying to get her to see the other cats already is way too soon, i tend to do everything in 2 week cycles, two weeks of isolation, then open the door and see, some cats dont want to leave the room for a while, some do, but as she is timid, it could take her a lot longer, and you also want her to be fine with you and coming to you before she is loose in the house so you can catch her if needs be. With a timid cat, I would actually be leaving it longer than 2 weeks before letting them see any other part of the house.