1 year old throwing up

My 1 year old (14 months) daughter has never been big with solids (since we started at 6 months - she didn’t actually eat anything til 9 months). She’ll eat about one small meal a day, but she usually just picks. She’s growing appropriately so ped isn’t concerned at all, figures she’ll just love foods later on. She has her few foods she loves. Once every few days she’ll eat a great meal, like a lot more than usual. I’ll get excited& happy she had a great meal but shortly later she’ll throw it up, almost as if her stomach isn’t used to eating that much foods if that makes any sense. Is this a thing? She’s my third baby but my older two took to solids immediately from 6 months and ate everything in sight lol. but I just hate that she’s throwing up everytime she eats a bigger meal.

Also, she throws up every single time we take a car ride(about once a week) I was even recommended via her ped to flip her car seat forward (i know this is dangerous - i didnt flip my older two til age 3.5) because she’s figured it has to be extreme car sickness setting in since it’s only begun two months ago when she turned 1. Does anyone have any insight on this as well? I’m worried about her throwing up and choking on it or something as we’re driving.

Thank you so much in advance, as I don’t have any friends with kids to ask for advice. xx