If you were getting harvest moon, I'd say neither PS2 or GC, but get the 64 version.
But either way, you didn't mention 64 in your list, so I'll just say that the PS2 version is definitely my favorite of the two.
Katamari Damacy is a yes.
Does she like to sing?
If so, Try Karaoke revolution

3 is my favorite so far, because you can play duets... It's fantastic when a large chunk of your friends are tone deaf.
Amplitude/frequency are great games, (I think you said she likes DDR?) they're pretty similar, except not... and much less exhausting.
Is she dead-set against violence, or is it just for major violence? because she should give Zelda: windwaker a try.
Trying to think of more videogames that are non-violent but still good.
Jak and Daxter: the precurser legacy is fun, if
slightly violent.