Good for you. Are the American people better off thanks to you and your mother's presence here? Or would they have got along just as well without you? That's the salient question.
I imagine they probably could have, but even looking at it from a strictly utilitarian point of view, both me and her are now American citizens producing a fair amount of value by plying our trade. I suppose you could debate whether or not skilled workers like ourselves were truly needed, but I think being able to find employment is a good enough proxy for being a productive member of society, so I would say the American people as a whole are 'better' than they would have been without us - although clearly this hinges on the actual criteria you choose.