Hi! Firstly, I appreciate all advice from the lawyer community here, and I appreciate any direction/help that non-lawyers can offer.

Title gives the summary. Here are some tl;dr facts:

-I am born and raised in Michigan.
-I have been dating a Mexican for almost 6 months now, and we are ready to tie the knot.
-She entered the country in April 2016, and she has been living with me since.
-She has a B1/B2 visa, valid Mexico passport, and birth certificate (currently only in spanish--ready to get a translated copy).
-Her I-94 was issued in January 2016 (she came to visit in January, and she returned to Mexico in February, and then she moved here in April).
-We are looking to get married next month, July.

Now, we consulted with a lawyer about a month ago, but we are hoping to accomplish the marriage and immigration process on our own to save the money. In consulting with the lawyer, she informed us that the I-94 expired in February because she left the country. My bride-to-be was not given a new permit to reenter in April; the lawyer sounded a little surprised by this, but she also made it sound like it was nothing to worry about. The lawyer told us that we have to wait at least 60 days from her reentry in April and also that we would have to marry before October in order to avoid serious issues. The lawyer also said that we have a very straight forward case for immigration, because here, she has no legal charges against her and has never spent any time in jail.

So, what I would like to ask and get some real legal answers to,
-When applying for the marriage license in my county, will her visa, passport, and English translated birth certificate be sufficient?
-Regarding the I-94, is it correct that we do not need that to get married? The permit itself says that it expires in July, but the lawyer told us that it expired in February because she left. Either way, are we safe to move forward without it?
-What are the next steps after the marriage license and wedding? Would I be filing the alien relative I-130 and permanent residence I-485 forms? More steps than this?

We know that there are websites and guides to help in the immigration process, and we would be happy to see more links and help from people. We just have a nervous thought in the back of our minds that if something goes wrong with the process that she will be forced to leave the country.

Thank you!