OK, someone has to say this--this thread seems like a collection of cheesy college application essays. You're already in grad school. Do you still need pads on the back? Here, good job, good job.
You know you did good work and made good choices. Other people know you did good work. But so did virtually everyone else who got into good grad schools. No one is going to look down on you for coming from low-income families or for being first generation students, and if they will--they're just a bunch of jerks.
I grew up in Eastern Europe and came to the U.S. at 19. My parents' combined income at home was less than $1000 a month, for a family of five, which wasn't much more when adjusted for PPP. Yes, I went to a college well below in USNEWS rankings than others I was accepted to, based on financial aid. Yes, I had to work crappy jobs in college. Yes, I studied while some other people went to Bahamas for spring break. Yes, I worked hard academically and missed some fun. But so did numerous other people from way wealthier families. In America, parents' income does not equal kids' income. A lot of my upper-middle class friends had to serve tables, work at supermarkets or for maintenance to pay their college bills, but they never asked for a pad on the back. I am well aware of the outcomes of my graduating class, and it's those that were motivated and worked hard that succeeded, regardless of parents' education or income. In terms of grad school applications, parents rarely ever know enough to be more helpful than, say, thegradcafe.
In my graduate program, the vast majority worked very hard to get here, and still work hard. Grad life is not a lifestyle of luxury for virtually anyone. Things valued in grad school are intelligence, motivation, hard work and humor, not family background.
So, I suppose it was worth answering someone who was unsure about the social environment and attitudes in grad school, but 5 pages of rubbing each other's egos for "overcoming the odds?" I thought it would end on page 2, at most. You've made it, congratulations! Now get over the "disadvantages you had to overcome" and get down to work to continue to succeed.