@Erica did the low iron have any effect on them! Like have you noticed any differences, better sleep, happier since you have been adding more iron!
I’ve read somewhere, and maybe do some research on this to see what you find. But I heard that high calcium can deplete your iron levels. I don’t know your situation but if your LO is having too much milk that can limit their body’s ability to absorb iron rich foods. Not sure if this is true but something to look into. Hope this helps!
Try giving them more oatmeal, beans and lentils. It helped my son a lot. Try to avoid giving it to them with Dairy. The calcium won't allow as much iron intake.
My daughter is the same! We’ve been doing Yum! Multivitamins with iron, and adding spinach/kale to everything!