Domestic Violence Incidents Lead to Clearance Denial

I have been a law abiding citizen all my life, with just minor traffic violations till about 2016, when my then 16 year old, who was experimenting with illegal drugs attacked me. I defended myself but I had failed to tell the police that she initiated the attacked because I was trying to protect her. She, on the other hand threw me to the bus, literally…because she was hurt (no weapons involved), the police arrested and charged me with 1st and 2nd degree felony assault.
I hired an attorney and on first appearance, the judge threw out and dismissed the first degree charge. Per my lawyer’s advice, I pleaded no contest with the stipulation the charges will be dismissed under the condition I attend anger management class, which I did…case was dismissed and expunged.
At the time of the incident, I was already a fed employee so I immediately reported the incident to my agency. I maintained and still hold a Tier 1 public trust clearance in my current position. Now, I got a lifetime promotional opportunity that requires a Q-level clearance and I am scared to death of leaving my current/secured job and risk termination if I accept the new position and denied Q-clearance.
My credit score is good and the only unpaid debt is my student loan, which is in good standing. My question is; will this one time incident with my daughter, (whom I will give my life for) be a basis for denial? Also,because of Covid19, the agency is moving forward with on-boarding me with the stipulation of immediate termination if I am denied Q-level access. Do you think I should preemptively hire an attorney to help complete SF-86 or should I wait till adjudication.