My Daughter Is 23 Years Old. She Gave Birth September

My daughter is 23 years old. She gave Birth September 2014. The pregnancy and birth were without complications. However, since giving birth she has been experiencing multiple issues, extreme weight gain, 5 kidney infections, and dizziness, that about two weeks ago has progressed to fainting. She is on occasion experiencing pain in her chest and numbness/tingling in her left arm and hip. Diabetes and hypothyroid have been eliminated as causes. She does have low blood pressure, but the Doctors don't seem to think that is the problem.