Well, just a little update: 

My girl is now getting hot by shaving her asshole and fucking it with the little 'rabbit tail' toy I brought her the last time I visited. It's just a neat little hard plug, (ceramic, maybe? I don't know) the smallest I could find in my hometown, and it has a soft little poofy tail in case it slips in. Not that that would matter; I'll bet that tail comes right out if the toy got lost in a tight ass and she tried pulling on it. But, the progress is that she can now fit the toy in halfway, and came while fucking herself with it. Also, it didn't hurt going in and out of her.

 It's all going according to my plan...