Dean would be a little more hesitant to stab if he was caught by a woman. Not so gung-ho with his knife, and trying to take things slower. He’ll still defend himself if he has to, but he’ll try to talk things out (laying on the charm real thick).
If Dean caught a tiny girl, he’d feel just awful XD As we’ve seen, both brothers flail when a girl or woman gets emotional on them, so some tears and he’ll be hard-pressed to keep her trapped. How dangerous can she be?
(If she’s sassy instead of teary, there will be many snark battles between them before they get anywhere. He can’t resist a sass off.)
Sam and Bree have more of a brother-sister relationship, and that would be enhanced if he grew up with her. He’d look out for her, and they’d grow close throughout the years, but he wouldn’t flirt with her. Krissy might not be his type, but he’d be more likely to flirt with her.