Who owns a copyright during divorce?

Hello all, During Covid, I used writing and music to combat the constant everyday crap. Stbx had left the family home, thank goodness and my creativity blossomed without him. Divorce is nearing some kind of end but I’m wondering if the creative work I did, in the hopes that it may become some kind of post-divorce career, would be half-owned by him? Any money made from these endeavors would have to be split? An agent said she cannot represent me unless legally separated or divorced. Can I stipulate that all earnings whether from work created before, during or after divorce go to benefit our children instead of giving him anything? Is creative material considered a marital asset? Thanks in advance.