It is possible that she didn’t notice the check. It’s also possible that she likes to take time off from complaining about paternalistic behaviors to sample the ones that work best for her.
While this appears to be a glaring example of self-serving selective feminism, research suggests there’s sometimes a more charitable explanation for absurdly contradictory beliefs and behavior. Though most people believe that there’s a single consistent you (or me) with stable beliefs and preferences, this actually seems to be an illusion. In fact, if there’s one thing that’s consistent about humans, it’s how inconsistent we all tend to be (and -- it gets better -- how consistent we are in vigorously denying that).
Cognitive scientist Colin Martindale theorized back in 1980 that we have a number of “subselves” -- sub-personalities with varying beliefs and priorities -- that go active or sink into the background depending on the context at hand. In other words, whichever goal is front and center in your mind -- like “Fight patriarchal oppression!” or “Take this totally adorbs patriarchal oppressor home to bed!” -- drives how you think and behave.
Research by neuroscientist Michael Gazzaniga suggests Martindale was right. Gazzaniga’s findings also led him to the conclusion that our mind has a janitor of sorts -- a psychological one he calls “The Interpreter” -- that tidies up in the wake of our inconsistencies by creating justifications for them. These, in turn, allow us to view ourselves as consistent and rational -- instead of laughably hypocritical, like a feminist who, when the check comes, stares skyward, all “Wow! That is one of the most well-preserved examples of the early-’90s popcorn ceiling!”
However, again, more charitably, everybody these days is confused about who’s supposed to pay on dates (and when and what it all means). For example, a woman will chip in on the first date because she earns a living, too! -- or because the prospect of sex with the dude is akin to “Would madam enjoy her Caesar salad with a light dusting of E. coli?”
To suss out where this woman is coming from, you need more information, and to get that you’ll need further interaction -- on the phone or, even better, in person. (Action reveals character.) Sure, she could be a hypocrite riding the patriarchal free dinner train -- or maybe she finds it icky to split the check and figured she’d get the next one. It’s also possible she’ll reciprocate with a home-cooked meal -- because you picked a place where the water alone costs $11 and she’s busy completing a dog-walking internship while moonlighting as a freelance field hand.