I've been back on the task of trying to find Lizette's last name. I've listened again to the track that we think has her name on it. Here at about 2:23
http://www.soundclick.com/player/single_player.cfm?songid=5676978&q=lo
I'm still hearing Madero or something very close to that. I've tried to google every variant that I can think of with no luck so far. I hear a definite ma sound at the beginning. That could be ma- or mo-, particularly if it's mon-. I've tried Montero, Monterro, and a few others. Nothing in NM so far. It could be just that she had no earlier web presence, but I doubt that somehow.
I did find tis though, which may help someone else. It's a list of hispanic surnames in New Mexico that start with m. Maybe someone who speaks spanish can do a better job than me of finding the ones that match the pronunciation on the recording.
http://www.hgrc-nm.org/surnames/GNMPD.html/surnames.html#M
Another thing that I've tried with no luck so far is to search for <3 and lizette. I don't know what <3 means, but she sometimes sings a comment that way. I can't get the "<" to come up in my search even with quotes around it. Anyone know if that's possible?