Whats in a name

When Issac and I went to get our Marriage lic in the states we encountered a nice lady behind the counter who had a gold heart on her front tooth. Gotta love St. Louis. She seemed to enjoy her job anyway. She was helping us fill out the form when she asked what last name I was to take. I said Hernandez. She said no you either take the whole last name on his ID, keep yours or hyphenate his whole last name with your last name. Well I was excited to take my fiances last name so I said ok Ill be Hernandez-Franco. So I got my name changed on everything like most newlyweds do. I did keep my old passport because that's just to much of a pain to change. When I had Alana I gave her what was now mine and Issac's legal last name. 
Now back in Mexico when we were in the doctors office for our OB visit the doctor crossed his brow and said, "Where are your parents from Amanda." I crossed my brow and said, "Missouri" I was thinking what the heck is my OB asking that for. The light then when on. AHHHH hes looking at my last name. In case you don't know in Mexico people keep their fathers last name and mothers last name. This does not change when they get married. So here this doctor is looking a very white American with that last name. I quickly nudge Issac and say,"Explain my last name." Issac then realizes the confusion and quickly explains to the doctor.
The other day we were filling out our application for Alana and I to get our FM3. They ask your father and mothers names, and then put a line for other names. And after reading some other blogs about the FM3 process I realize they will most likely make my ID under the name Seyer-Wicker.  So Issac and I decided we would call the immigration office to decide what to put on these lines and what is the best option from here.
At this point we have decided to get remarried here as to acquire a legal marriage lic in Spanish from Mexico and not have to go through as much U.S. bureaucracy to get ours from there. When we go I will produce my passport and birth cirt which has me as Amanda Seyer. And when we register Alana we will show the same items.

Therefor in the U.S. our legal names will be Hernandez-Franco, and in Mexico my legal name will be Seyer-Wicker and Alana will be -Seyer, along with our other kids.