Apologies for this intermission in the story but I've been asked a bunch of questions from readers who have heard different things about the immigration rules and laws that Lizzy is operating under and wonder how this story could be true. First point is that this is fiction - so I do have some license to play with reality a bit. That said, I have tried to base the premise of the story and the events in their lives on how the laws of the US exist today. To be clear, I am not an expert but have done research and I am familiar with the laws as they stand today. I also have a good sense as to how Harvard deals with these issues. I don't know about other schools/universities and I will admit that Harvard is progressive.
So, as the laws stand, a close relative (e.g., parent, child, spouse) can sponsor their family member for a green card. The catch is that the relative has to be 21 or older. Lizzy and her parents don't have a 21 year old relative who is a citizen (well, Lizzy does now that she's married) to sponsor them for a green card. They need to wait until Maria is 21 to have her sponsor her parents. The key is having an adult immediate relative. There are also ways for employers to sponsor employees for a green card - but Tomas is an independent business owner - and he can't sponsor himself. There are some laws that enable business owners to get green cards but they require an investment of over $1mm and need to generate a certain number of jobs. Tomas' little restaurant doesn't qualify. Given the way the laws are written today the Benetez family would be stuck.
Harvard does provide full scholarships for illegal immigrants. Not often but it has happened. I can't comment on how any other university handles it. There is only one tuition for Harvard regardless of where you are from and there are very generous financial aid policies. They are "need blind." If you get accepted they will find a way for you to attend - even if you can't pay anything.
Now to the restaurant. Tomas bought the restaurant and land with cash and a loan from a local "black market" lender. He used Maria's SS# to set up the business and file everything - that's why the restaurant is in her name. He's always operated it on the up and up...paying taxes, etc.
As it stands, Lizzy could try to find an employer to sponsor her but generally employer's are only willing to do that for skills they can't easily get in the US job market. There are very strict limits on the number of work visas issued in any given year. As such, its possible but unlikely she could get a visa that way.
I hope that answers the various questions I've received.
Cheers!
P.S. I love your questions so keep asking them!