Dealing with stressful situations?

Me and my aspie wife get along great and communicate well 99% of the time. We can work around the usual "difficulties" in daily life pretty easily due to good communication and either of us being upfront on miscommunication, little spats based on one of us not understanding the other's intent are often diffused quickly by talking it out since we never yell at eachother. In the last year we had our little girl, which has added a whole new element to our relationship naturally. If there's something stressful going on (e.g. Little one's chronic constipation and medicine to sort it, or if she's unwell) my dear other half can get very wound up and tense about the smallest cold, and when she's stressed out she doesn't put the same effort into her expressivness if that makes sense.. Making her face tie up with her emotions isn't the priority then. So often she can seem distant and glazed over, or excessively emotional in these situations. Which stresses me out because visually to me she's "closing off" or "overreacting" even if rationally I know it's not as bad as it looks. When I think she's over stressing I get impatient, because when I'm trying to be supportive and do my part to look after the little one I don't have time to be fretting about propping her up emotionally or trying to interpret a blank face just because our girl has a small cold. This makes me irritable and snappy, and understandably Mrs might not follow why I'm annoyed. Overall we clearly can't avoid kiddie illness but those situations just make our communication much harder and neither of us need to be faffing with that extra layer of interpreting eachother. Does anyone else have this issue? Any recommendation on how unavoidable stressful circumstances like thus can be made easier between us?