ahh, don't know how I missed that flag. But yest that did it. All good now, thank you.Wow, the massage oil should have become available much sooner. A possible fix is to go into the cheat console, Flags console, increase Mom's "64. massage_oil_available" to 1, visit the sex shop to buy the oil and try giving her a massage. You should be able to continue with her path.
Also noticed that you missed Mom's photo #40, to get it repeat the scene where she gives you a handjob (visit her bedroom at 22:00) then once you're back on the hallway try to reenter her bedroom.