Try giving her water, I know doctors advice not to give new borns watet but I'm giving my daughter water and it works
I use similac sensitive because my sweetie was constipated from the advanced similac. My dr also said she can take miralax so I would call her pediatrician. I hope this helps
You should talk to her doctor about miralax.
I believe we used a Nestle formula that came without iron.
Gerber good start gentle with iron