Adjustment of Status - I-485

Hi, everyone! I'm new here but I've been reading all y'all's comments for months just to help me be informed. I'm kinda nervous but I was wondering has anybody been to the Irving, Tx Office lately for a AOS interview? I'm a US citizen and I petioned for my wife. I felt like the interview went great! We had a very friendly IO there and the whole process maybe took 15-20 minutes tops. She even said she would approve us for the 10 year card as soon as she gets it back from her supervisor. So we weren't immediately " approved" but we still haven't heard anything since then. Our interview was on July 27, 2017. It's been almost 3 weeks and nothing. I've read a few other cases and alot of people seem to have an a answer almost immediately. Weve been married for 4 years and we own multiple things together and even have children together. Is it normal for them to give the case to a supervisor? If so how long must we wait before we try and contact them? I would appreciate any response. Thank you !