Kissing Cousins

I have a friend that lacks common sense and a little book sense.  I'm not putting my friend down I'm just giving you an idea of what I deal with. She is very..... What the word for a little slow.....  She can be manipulated to someone any thing.  She believes any and everyone who tells her something. Example: We both have 5 month old babies they are just a week apart.  Someone told her that of her child gets sick she can't take her child to his primary doctor only to the ER.....  That his primary doctor only gives him shots. Now before you say that might be true depending on her insurance or the doctor she uses.  We use the same doctor office. We don't have the same insurance but I'm pretty sure if your child is sick you can take your baby to the doctor just make and appointment or walk-in....  Any I couldn't forbthw life figure out why she acted this way.  But now I know her great grandparents are first cousins, so are her grandparents, and her parents. Now don't say that doesn't matter.... I very well think not has to do with genes and the way she was raised cause they all act a like......