Pick your stereotype. Use it. Break it.
Do you need a dizzy party girl? Great. She dresses like a dizzy party girl. You've heard her talk like a dizzy party girl. But you see her at lunch, alone, scribbling and thinking and scribbling; then she rolls her eyes and scratches a long line through it; just as her friend arrives.
"Hey, what are you working on?"
Brittney looked up. "Hey Gina. Nothing. I had an idea, but it won't work."
Gina spoke as she took her seat. "Well I'll turn that frown, upside down, because guess who came to see me yesterday?" She leaned in for emphasis, "Jeff Davis!"
"Oh my god!" Brittney said, grinning. "Serious? What did you tell him?"
The girls talk, they get up to leave, and you walk by the empty table, and spot the page of scribbles Brittney was first working on, with that final line drawn through it. All densely compact handwritten physics equations.
Now, you can say this is a trope, but it isn't a stereotype. Tropes are things that have been used multiple times in stories, but that doesn't make them instantly recognizable to the general public.
Stereotypes are easily recognizable, and the stereotype of the "dizzy party girl" does NOT include any expertise in the mathematics of quantum physics (or any other science); nor does the stereotype of the nerdy science girl include any elements of the frilly party girl.
So, even if you think my example above IS just switching to another trope; the prescription is the same: Be creative. Include a trait or characteristic that, in your own mind, just doesn't fit the stereotype you need for the role. In this case, being a party girl, and fashion girl, and gossipy girl, does not require being academically challenged or mathematically incompetent. Her choices for fun can be divorced from her professional choice.
IRL people are often born with natural talents, and they pursue those talents because they are fun (often fun because they are praised for being good at them), and that may become a profession or life-long hobby. But that talent doesn't have to be the only way they have fun; culture also determines that, and it isn't that difficult to separate the two things.
Pick your stereotype. Leave it recognizable, but break it. Take something central to the stereotype and invert it, or discard it, or add a disability -- She loves fashion, but she's color-blind, but also not embarrassed by that, because it is who she is.