Lol you guys are putting waaay to much thought into this fighting girls thing! I am the only girl in a class of 20 guys and as you'll all know hands and faces end up in some less than ideal places regardless of if your fighting a guy or a girl.
But trust me girls who fight in bjj classes with guys are comfortable or they wouldnt go. they put no more thought into where your hands are on them when rolling than the other guys think about ur hands touching their ass or u shoving your balls in their face for a triangle, our focus is on trying to emasculate you lot by choking you out on the mats lol
so chill out about it, its no big deal to us so shouldnt be to you!
hope this helps