@
oman
While I am sure Shelley doesn't mind, make sure that if you change them with the intention of sharing them in any fashion (even if it is for someone who can't edit them for themselves and you give them directly to the person) that you get her permission. For the most part her gfx packs specify that they can not be redistributed in any way.
Again, that is a formality and a courtesy, I am pretty sure she wouldn't mind since it was shared with the intention of being modified but modification and distribution are two different things, you are better off asking her first.