From my experience you will not have peace of mind until that day in court when everything is finalized!! The day it did happen though was the single, best day of my life!! Every single day was stressful that either one of the knuckleheads would show up and disrupt our lives.
There are way too many variables for me to even guess what your odds are of getting this adoption granted. It seems strange to me that your mother had her for the first 2.5 years of her four years of life and still has conservatorship yet you have been raising her for almost 1.5 years. Can your mother just give her to you legally?? She doesn't seem to be living up to her obligations.
I truly hope you have an amazing, brilliant, kick butt adoption attorney....not some unreliable basic family law attorney. That was one thing I didn't try to cut corners on. I also found it much more productive to NOT expect or request child support, communication or gifts. That just opened up the opportunity for them to have any connection with my daughter.
I hope for all of you it gets resolved soon. My daughter was pretty dialed in on the situation when she was two years old.