Scared New Mommy?

My doctor diagnosed me with preeclampsia during my pregnancy, which caused me to have my baby at 34 weeks. My baby was discharged from the NICU 3 weeks ago at 3lbs 10 ounces.Im feeding her in hopes to help her gain weight. she is still soo small,, is it safe to also give her water and im wondering why her skin very dry and shedding.