Hey, thanks for the kind words.
Mom's Secrets should be hidden in the old ledgers in the bureau. Check the ledgers, and then a new Option should appears to find some inconsistencies in the docoments. Repeat that once or twice until Gina uncovers some secrets, then confront Greg.
Might check the Quest description and add some clarity. 😓
Also, here's the ingame questlog. The guide tab has a step by step guide for every major questline.