Part-Time College Student?

We & our daughter want her to try being a part-time student next fall, combined with working part-time. She will be a transfer student to a large state university. She currently has 87-100 credits (depending on which school you talk to) but has been struggling, particularly this past semester. She has some specific needs that make taking just 2 courses per semester a good option.
What do we need to know about going part-time? Are there ramifications we are not thinking of?
When do we tell the university that she only wants to go part-time?

For most majors, there is no problem at all (especially at big state Us) if a student is part-time. Has she been admitted yet? If she is still applying, this could be something to discuss with the transfer admissions office. If she has already been admitted and is ready to enroll in classes for the fall, she needs to speak with her department to plan her program of studies. That would be a good time to sort out how a part-time program can work.