Factory reset and language question

[brysg2]

Hello all. I'm currently running CM7, and I'm about to wipe the phone back to stock sense as I'm going to be giving it to my mother when the Epic Touch comes out. I have a few questions. Do I have to flash back stock first to do a factory reset, or can I go ahead and do so with CM7. Also my mom doesn't speak much English so I was planning to change the phones language to Chinese for easier use. I see that CM7 has her native Chinese language installed. Does anyone know if sense has this as well? Thanks in advanced!