One of the group is burbling about how she's able to use the strength she drains from others and it dawned on me -- how does she know that?
She doesn't, that's the trick. I do, but that's because I'm the author.
Mind you, she's dunderheaded enough to have not noticed how the heroine could have the draining power AND superspeed, because powers are random, even in combination. But the doctor they are talking to should point it out quickly, and investigate the evidence. Should be easy to establish because -- she can't do it now.
Unlike, saying, discovering whether she can talk to duck-billed platypuses. (She can't. But I think only I will know that.)