I have a philosophy with both my asd kids and that is you'll never know until you try. Whenever they make changes in my daughters iep I agree to a trial. They monitor her for about a month and no issues then I sign.

I agree with Sumrae, start off with a trial. If you don't lile how things are going, you can always have them change it. If she does get off set by the slightests changes, I would request a para. Between having a para and a teacher in her room, it would be rare that they both would be absent on the same day. It allows her to have two adults that will be able to comfort her incase there is a change in the room. Personally, I would go for it. Especially at this age, the transition will be easier than older grades. Self contained and mainstreams rooms are so very different that it's an even bigger environment change when they are older.