Unlawful entry isn’t a problem for DACA, but it is a big problem for a marriage-based green card, with certain limited exceptions. A lawyer can explain in further detail, and in your situation it is highly recommended. If anything is unclear after you speak to an immigration lawyer, feel free to post further.
One problem with answering a question like this is that everyone’s circumstances are different, and how long it takes, and how complicated it gets, really depend on the individual case, as Eva Luna said. Even two almost-identical cases might not go the same way, depending on the people who process your forms and conduct your interviews. While there are basic standards that all applicants have to meet, the scrutiny that each application receives, and the extent to which the application is held up, can vary greatly from case to case. At least, that’s what i’ve learned, based on my discussions with other people who have gone through the process. Sometimes it’s also just a matter of timing; applications submitted in some particular months and years seem to go more quickly than applications submitted at other times, depending on the backlog and the amount of resources available to the folks at USCIS.
I think that i must have had one of the smoothest possible Green Card experiences. I got my Green Card in 2009, based on my marriage to a US citizen. I’m an Australian/Canadian dual citizen, and i was already in the US on an F1 student visa.
I began collecting the forms and required documents in March of 2009. In that same month, i organized to have all of the relevant medical tests and immunization shots. I mailed off all my forms on April 6, had my biometrics (fingerprints, pictures) taken in the middle of May, and my wife and i had our in-person interview with an agent on June 19. On that same day, i got final approval and had a 1-year Permanent Resident stamp placed in my passport. The actual green card, valid for 10 years, arrived in the mail two weeks later.
So, basically four months from first downloading the forms to receiving my Green Card. No lawyers involved, and the whole process was extremely painless. Far easier than i had expected. But, and this is the important part, my circumstances ticked all the right boxes for a fairly straightforward case.
I don’t come from a country that is on the terrorist watch list, and nor am i from a country that sends a lot of illegal immigrants to the United States. I’m a white guy who speaks English as his first language, and i have a post-graduate education, all of which made it easier for me to negotiate the forms and bureaucracy, and probably also reduced any concerns on the part of immigration officials themselves. At the time of our interview, my wife and i had already been married for five years, so there was little suspicion that we had gotten hitched just for the Green Card. My wife also had a decently-paid professional job, ensuring that she could support me financially if necessary, as required by the immigration process. Basically, there was nothing in our circumstances to raise suspicions.
I will only add that my mom became a citizen within two years after a applying, though they make you wait five years. Another relative with a green card also got it after two years after my mom prodded her, even though she did not believe my mom and thought she would wait five years.
Just putting that out there.