my DD who was an early talker and has a penchant for "fancy" words also like Eloise alot, not because the vocabulary is more complicated, but I think she likes the way it sounds when read aloud...

Why not just move on to higher level books and insert your own commentary? We do that trick quite often..."delirious is a fancy word for crazy", "furious is really really really angry", etc...you could move to a more complicated book and expound on the vocabulary in the same manner

I get excited when the library lets me know my books are ready for pickup...