Re: dirty uniform
Reminds me of the time some guy hadn't washed his feet and tracked dirt all over the mat. I loudly called him out for it, he hastily apologized and bowed out to take care of it, and it never happened again. If someone's head will explode because the owner of a makeup-smeared keiko gi complains, how will they ever deal with the other stress that comes with studying a martial art?
With that said, one doesn't necessarily want to blast beginners off the mat for their first etiquette infraction. So you might want to mention it more discreetly. Just be matter-of-fact about it: you don't care what she does off the mat, but remember that aikido is a full-contact practice.