^I agree. While you wait for you GC, DO NOT go abroad. You can find plenty of volunteer opportunity where you live (or can you work with your current visa?)
I agree it may take a long time but realistically this student without a green card has to pay 55K to attend a UC vs. with a green card they can attend for less than half that… waiting for a year would be the easiest 120K (30X4) that student would earn. And if it takes longer then the situation isn’t the same, but s/he should at least try this.