In my experience, kittens are vaccinated at 9 and 12 weeks, so if she is only 11 weeks, has she completed the full course anyway?
I would not put her in a cattery at that age, she needs constant attention and motivation. Can she not go back to where you got her, so at least she is in familiar surroundings, with people that she knows.
I always ask people if they are going on holiday who want to re-home one of my babies, I always say I will not re-home them until they have returned, but will reserve them for that time.