@ZephyrHeart hm hm that's a tough one haha.
I forget what your plans were for Megan, wasn't she supposed to be a yoga instructor ? Maybe grace forces marley to go to yoga with her because she gets a free coupon, and then obviously megan is the instructor (if that's what you planned) or maybe also taking the class, they bump into one another briefly (asking for directions/ something similar.) Later on, grace meets hazel, and of course believes she's megan.
Marley needs a tutor, and is paired with Megan, and grace never explicitly meets megan, (i think i just remembered you changed her name lmao) they're going to some sort of event and bump into megan (concert, yoga, something of the sort) and grace and marley run into megan. They dink around and catch up for a while (grace is somewhat absent from convo) and then, she meets hazel.