I almost want to pick Waterson here. I think she's old, shopworn, and has one foot out the door... but stylistically this is not a bad fight for her on paper. I think Michelle (an Atomweight masquerading as a Strawweight) will actually struggle more with the physicality of Gillian (a career Flyweight) than the offensive grappling itself. Waterson's TDD is, statistically speaking, pretty good. She fought Esparza in 2020 and stuffed nine of Carla's ten takedown attempts while also getting controlled for less than a minute, which is pretty remarkable. She also stuffed all five of Pinheiro's takedown attempts. Michelle in general, despite being known for her karate, has always been an underrated grappler (sort of like Pettis in that regard). She's never been afraid of going out there and wrestling with girls or submitting them. That being said, Marina just put a really bad beating on her and also managed to take her down despite being a pure striker... and she also got clubbed-and-subbed by a brawler in Lemos fairly recently. So it's possible that the version of Waterson we'll be getting here will be very diminished at nearly 40 years old fighting a much bigger girl who will be trying to drag her down and outgrapple her from bell-to-bell.
Conversely, as much as I like Gillian, her game falls apart completely if she can't secure her takedowns and positions on the mat right away. She has remarkably little to offer on the feet. Assuming Waterson stuffs her early, I could see her picking Gillian apart down the stretch with straight punches and side kicks.