You remember that Carol led Kirk into the shuttlecraft for a reason that Kirk didn't understand, right? "Where are we going?" he asked, or something like that. If it was just a professional conversation, they didn't need to be alone like that. She led him in there in order to change in front of him, pretty clearly. If she'd wanted privacy, she could have asked him to wait outside for a moment, or changed ahead of time, or afterwards.
On reflection timing aside this idea is weirdly attractive - although it still doesn't seem like a likely way of going after an adult
ongoing relationship to me, but that could be cultural skew on my part (Australian, female).
It'd work if she saw Kirk as a floozie and was after a quick bonk, no strings attached but given their situation it was an incredibly inappropriate time to be going after him - IMO you'd have to posit Carol has the same emotional age as Kirk...
I doubt the writers thought about that much, IMO they just took a lazy approach to getting Carol out of her clothes, YMMV