Too much non-relevant info and not enough details.
First, being a member of the Alphabet Tribe has no bearing on whether she needs a return ticket.
Secondly, is she an American citizen?
This would be simple:
If she is a returning green-carded Filipino, then no.
If she is an American (or non-Filipino), then yes.
If she is a former Filipino, then no (Balkbayan).
If you're Filipino and she is non-Filipino and you are traveling together, then no (Balikbayan)
That covers all the scenarios I could think of.
If she a crossdressing, gay, African-American, combat veteran with one leg and eye, the above still holds.