I agree - I did Crossfit for years (have given it up now due to knee trouble) and even in my provincial little U.K. town there are strong, beefy Crossfit girls who can push press 70kg for a couple of reps. I mean that’s their body weight, which means if they have smaller framed friends then that’s girls overhead lifting girls for you. On that note don’t underestimate how competitive these Crossfiters are. If one (finally!) agrees to whatever it is you want - a flex, a lift, an arm wrestle, etc... then others will inevitably join in.
Either that or the gym.
No coincidence that you meet muscular women at places where they gain those muscles.