Your question is a crystal ball question and no one will be able to answer you 100%.
That being said, circumstances surrounding your incident, parent and child, vs. partners, time lapsed without repeated behavior, are big mitigators in your favor. List everything and be prepared to discuss in an interview. If you have no other blips, especially related to arrests or violence, I would be more than confident that you will obtain your clearance.
I wouldn’t bother with the lawyer. Just answer the questions on the SF-86 completely and honestly.