Heroe

Hi. Me (beneficiary) and my wife (petitioner) sent the AOS package a little over a month ago, including I-130 + I-485 + I-765. We sent it right after we got married. After that, my wife changed her last name to mine. In the AOS documents and forms that we filled, we used always her maiden name since she hadn't changed her name yet. Now, we just realized than in the NOA, it says "notifiy the USCIS if there are any changes in the personal information". I just called the USCIS National Customer Service and they told me we needed to send a letter explaining the name change and include any supporting evidence (like her new social security card). However, I still have a few questions that maybe somebody here can help me solve:
-The guy told me to send the letter to the address that appears in the NOA. In my case, it is an address in Missouri, which I wasn't expecting since we live in Texas and we sent the AOS package to Chicago. I assume from Chicago they sent it to Missouri and that's where they're working at it right now?
-What should I say in the envelope? I'm pretty sure I need to put the receipt number, but what else? "Update"? "Name change"? Or just nothing else at all? I bet it's not very common to notify the USCIS about the petitioner's change of name, but I would appreciate any info regarding letters to the USCIS notifying address changes or phone number changes, since I could probably use something very similar in the envelope.
-I was planning on writing a very brief letter just explaining that the reason why she changed her name is because we just got married, and also include a photocopy of our marriage license, and her new social security card showing the changed name. Am I missing anything?
-There's been a problem with my wife's name change: I have two last names (two different words) and she only wants to have my first last name as her last name. When she got her new social security card, she had no trouble and she officially changed her last name to my first last name. However, when she tried to change her driver license, they wouldn't let her keep only my first last name and she was forced to have both of my last names as her last name, since both of my last names appear in the marriage license. We are now trying to legally change her last name to only my first one, using a court order. Since the USCIS seems to 'care' more about social security information than driver licenses, I think it makes sense to tell the USCIS to update her name to the one that her social security card says, which is also the one that she's ultimately going to have in her driver license.
Thanks in advance.