Shannon,
you said:
I'm not sure that everybody can quite control their emotions appropriately iykwim.
I think that there are very few mothers with a child/children 3 or over who has not "snapped" in some way eg. either by yelling at their child or giving the vice like grip a little too hard! Remember ,we (mothers) are only human too and if we are not feeling 100% ourselves and then have the people we love most, push our buttons then it is difficult not to respond in some way. And you have additional stresses with your special girls. so don't be too hard on yourself. You sound completely normal to me.

Cailin, you do sound like a saint LOL but there have to be some on this earth!
I get very sad and embarrassed seeing those parents who yell and swear at their kids and expect that to have some positive effect on their behaviour.