Certainty is a strong idea, so I like to play it safe and give *everyone* the benefit of doubt. I wouldn't say I'm anywhere near 'sure' on her, or for that matter anyone from BP, Twice, or Itzy (since some people mentioned Yuna, and even Wonyoung from IVE).
*Every* member of BP in particular has the oddest physiology, oddly legs along with different midsections, but Jennie and Jisoo definitely have girls' facial features.
As for Lisa, the fact she's such a tomboy just makes things worse, because traditional "tomboys" are pretty much non-existent (here in Western countries at least), since gender ideology rendered them either clear lesbians, or women who openly identify as men. There is no need for 'tomboys' in the traditional sense of the definition, it was nice when they actually existed though. Those were the good days.
So if you'd really like to be 'sure' of any of this, such as Lisa's case, it could take several years, since males develop a more masculine face as we age. That said, Solar and Hwasa are both definitive m-t-f idols, case is closed on 3/4 Mamamo members and I'm 100% - either they're mtf's, or MAJOR anomalies.