[@Reia]
When I say "no monsters", I generally mean larger or more powerful beings. Things like shapeshifting dragons, arachnee/driders, lamia/gorgons, ancient vampires, etc. While something like a werewolf might be bordering on the very edge of what I'd allow, a weremouse is - I assume - a rather 'weak' type of lycanthrope, generally speaking of course. So I don't mind.
Just expect people to treat her rather poorly though - even if she is a chubby, adorable mouse-looking thing, jerks are still racist jerks. :P

[b]EDIT:[/b]

Oh, and I also read through both Cecilia and Branwen's sheets. They look just fine to me. :)