Sometimes when i have friends and family over she can get overwhelmed and she will yelp and run to a 'safe spot' which is understandable but when it's just one friend over she will sometimes allow herself to be pet but will randomly yelp and avoid my friend but still allow me to pet her. I know my friends aren't hurting because I'm way more rough than they ever are when we're playing and she's never gotten hurt by me? I got her at a shelter when she was 3 months old so I know nothing of her past, could it be some sort of leftover reaction to strangers in her old home? Or should we get her checked out?