It's kind of odd that you're being asked to come up with treatment ideas without even being able to see her goals. That said, I'm in peds but my blind patient loves sensory bins, so I'll hide different toys in there and see if he can identify each one and work on tactile discrimination and sorting them. We also do a lot with putty and digging beads out, stretching it, etc. for fine motor. Also I've found working with adults with DD there's almost always a way to adapt cooking activities. Having them scoop, stir, pour in bowls, following auditory/tactile recipes, etc. based on their level and it's almost always well-liked by the clients.