I have a friend that has her Mexican passport issued here in the USA but has not yet been stamped by Mexico. Can that be used as an ID to travel anywhere in the USA by airplane, or does she need an ID from USA?
As you can see from the TSA page on ID requirements, a valid "foreign government-issued passport" is sufficient without any further requirement.
TSA officers only look at the ID page. They do not concern themselves with whether the passport has been used for international travel.