It sounds like you might need a relationship counselor just as much as you need immigration advice. Yes, as you say, marriage is very serious, and if you’re feeling pangs of doubt it’s wise to avoid taking that major step until you are as sure as you can possibly be.
As far as the legal commitments once you enter into marriage, there are many. There are the obvious ones – your girlfriend would by law be your next of kin for starters – and then the immigration ones.
Marriage to an American citizen allows an undocumented spouse to be sponsored for permanent legal status here based on the union. Obviously that’s a big enticement for some to tie the knot, especially for those who have no other prospects for becoming legal here.
But make no mistake, once the marriage takes place, it isn’t something that you could “move on from” fairly quickly, and hopefully you wouldn’t have the need to. As a U.S. citizen spouse you would be able to sponsor your wife for a green card as an immediate relative, which would put her on a faster track for legalization as opposed to all other kinds of applications.
Your email didn’t say where you live, but you could expect a wait of a year or so, give or take, before her case would be processed. There is plenty of paperwork to fill out, and required personal interview at the nearest U.S. Citizenship and Immigration Service (USCIS) intended to show the validity of your marriage – i.e., that you didn’t enter into the union solely for the purpose of obtaining immigration benefits for your wife.
One thing to bear in mind is that you’ll have to complete an affidavit of support document, which promises that you will accept financial responsibility for your wife if she ever became a public charge – in other words, if she required assistance from the government.
The affidavit is a legally binding document that continues to be valid even in the case of divorce. The affidavit’s legality ends when the person it’s intended for becomes a U.S. citizen; or accumulates 40 quarters (10 years) of work in the U.S. It can also end if the person leaves the U.S., thus rendering status here null and void.
A green card obtained on the basis of marriage is issued conditionally for two years, if the marriage is less than two years old at the time of issuance. After two years have elapsed, the couple must apply to have the condition removed, and the status upgraded to permanent.
This joint petition is best filed when a couple is still legally married. If a divorce were to occur during the two years, the immigrant spouse would have to file a request for a waiver of the joint petition requirement. This waiver is very difficult to obtain because the validity of the marriage is called into question, given that it ended so soon.
As you can see, there’s way more to your possible marriage than you thought, so make sure you make a choice that is right for you.