Thanks all!
I'm going to visit the person the hosta came from tomorrow, so I will get a more precise measurement of its mature size.
Larry, yeah those spots on the leaf edges are what I'm talking about. I don't know if they are insect damage or what.
I am constantly fighting plant fungus here, so I'm wondering if that could be the cause. Or if it could possibly be getting a bit too much sun? My neighbor has a very advanced case of it tearing through her hostas, so I am trying to prevent that if possible.
And my knowledge of hostas is very limited...