Not that I'm complaining, but I'm curious when the fandom collectively decided that Fluttershy was an F-cup. It's not just you; like 90% of the fanart out there draws her that way. Where did that come from?
Most of the girls I know who are shy and timid like Fluttershy are very busty and very curvaceous. Quiet/shy/timid = BUSTY/Curvaceous in my experience.
Seriously though she needs to go ahead and help wipe her down. I'm sure she wouldn't mind.