I have been having a mad crush on my kids' pediatrician
How do you feel about her?
I like her and I think of spending a night with her after my kids left
No matter how attracted you feel to someone else, you should never be unfaithful to your significant other. Do you really want to destroy your marriage and child by acting on such lustful desires?
I think she couldn't give a crap about my marriage and even if my girls get hurt, how does it matter to her in the long run?
It doesn't matter if she doesn't care for your family, your family will definitely care about what you do. I think it's wise to just switch to a new pediatrician, because hurting your wife and children by cheating will only cause life-long problems.