Xiaolang knows Kuro through karate (he's his Karate Dad), so there's a chance he may have mentioned Suzu to him at some point, at least in passing? Given he's like... one of the younger people on Retrospec though and prone to running into dangerous situations a lot because he's a dumb stubborn boy, she totally free to mother-hen him!!

... and also they can be stupidly gullible together as well, because being book smart doesn't mean you're smart-smart