I don't think you should be berating yourself quite so much When children are very young; it's impossible to sort out what is going to cause a problem and what is normal, inherited, or whatever development! All the symptoms could mean a zillion different problems.

When I was 42, I started getting slight nausea and decided it was time to get glasses! I got glasses and it didn't really help. Took me over six months to realize that it was left over Meniere's Syndrome I'd had since I was 38! It just didn't show up conveniently and at any particular time and I hadn't had a bad attack for over a year. And I was an adult and had never had much wrong with me, ever, so it's not like I had as complicated a medical history as it sounds like your daughter might have had.