My youngest son likes to store food in his cheeks. I don't remember if he started so young (he just turned 2), but we sit with him and watch him, and if he starts to store his food, we try to hold him off from taking any more in and tell him to "chew, chew, chew" while demonstrating what that is by making the chewing motion ourselves (and we try to make it sound like it is fun by our tone of voice). This has worked pretty well with him, except when he really wants to put more food in his mouth - he'll get upset and it worries me because of the possibility of choking, but we can usually avoid it escalating if we stay on top of it and remind him to chew before he reaches for the next piece. He knows what we mean now by "chew, chew, chew" and he thinks it is funny, like a game. I don't think it is a problem if she doesn't have teeth, as long as any 'hard' food can be softened by her saliva and chewed with her gums (my boys only had a few front teeth by this age so they were chewing with their gums, I'm sure).
If she doesn't catch on with the "chewing game" (11 months old is prety young for following directions and mimicking your actions, but don't under-estimate her, my babies have always surprised me, so give it a try several times), but if she isn't catching on, I would hold off on hard foods and stick to softer, spoon-fed foods that will not store easily in her cheeks. She has time to maintain her grasping skills while she is playing, and there will be plenty of time for her to feed herself. And you can try again in a month or so.
My little "squirrel" fell behind on the charts, too, toward the end of his first year, (he started out above the top at first and stayed up there for several months, then slowly fell back to below 50% and stayed there, and my doctors did not express any concern). I would ask your doctor specifically "why" she is concerned. And if your insurance covers the therapy, I suppose there is no harm in it and could only benefit your daughter (although this is a little outside my realm of knowledge). I have just seen friends worried by their doctors about their babies' growth for no good reason. So don't worry unnecessarily and ask specific questions because I don't think it is a problem just to fall behind in the charts, as long as she is still growing at a relatively steady pace.
Good luck and don't worry! She sounds absolutely adorable!:)