There is a mention of $400 towards high school fees causing some anxiety among her parents, but beyond that, not too many concrete details.
The focus of the article is on the writer's experience with the shame she experiences because of her parents' job, so perhaps it's not the right place for this information, but the composite picture would be a much more faithful representation of the overall experience of Jessica's.
This is also a point where America needs to introspect, as a nation: sure, we import less-fortunate immigrants, in large part because they are much more willing to do dirty jobs such as gathering cans, but it's also true that it all comes out in the wash: society as a whole is responsible for bearing the costs of keeping these people fed, clothed, schooled, and taken care of in medical emergencies. If you added up the costs, is the labor "cheap" anymore, or does it make more sense to discourage the immigration of what is likely to be a 2-3 generation underclass, and incentivise people already here to step in?