You can do what you want, but personally I wouldn't do MC so long as she's still seeing OM. Wayward's are numb to giving, or receiving, emotional needs so long as they're still all fired up with the brain chemical rush of OM/OW.
I see signs that what you are doing is getting to her, indeed. I think you should keep up the distance, and the GAL stuff, and do NOT give in to ANY suggestions of cake-eating. Going out to dinner with her is exactly that! It's an attempt by her to "normalize" the status quo, and gain your acceptance while she waffles and eats from two nice plates of cake.
In fact, I think it's time to ratchet things up some more.
