Since you are clearly on your peds rotation, you'll be more successful in dealing with parents if you make the following assumptions (no matter how ridiculous they may seem in the situation - eg abuse cases)
#1 All parents love their kids
#2 because of assumption #1, all parents are doing the best they can
#3 it is insanely stressful to have a child in the hospital, which makes it harder for parents to complete assumption #2
A little story - I'm a PICU attending, board certified in both general peds and pediatric critical care. I know a lot about kids, know even more about sick kids, know a lot about what life is like in the hospital...thought I knew a lot about what it was like having a child that was sick. My daughter at 3 weeks old loses her ever loving mind one night, seriously 8+ hours of screaming. Go through my normal little checklist of what it could be, try some things at home, etc., nothing works. Make the decision to go to the Peds ED thinking it was a corneal abrasion. Check, nope. Based on some of the risk factors when she was born, ED attending starts laying out the case for admission, cultures including LP and so on. All things I had told parents a thousand times. Get admitted, luckily everything goes okay, but that weekend was by far the most stressful weekend of my entire life. For a baby that I knew wasn't that sick, for a baby that all of my training told me didn't have meningitis or any sort of serious medical condition. More stressful than anything I've ever encountered - relationships, college/med school exams, clerkships, PICU fellowship, my grandmother dying a week before taking my board certification exam. None of that came anywhere close to that weekend and I'm undoubtedly more comfortable in the hospital environment than 99.9999% of the population. But in that moment, so much is out of your control as a parent, so much is uncertain and your mind just short circuits.
I'll add, that the above assumptions work for family members of adults too, but with the added issues of unpacking decades worth of emotional baggage that those relationships (spouse/parent/child/sibling) have created.