Missy is just coming up for 6 months old now, and the biting has become a real problem .
She is not play biting but biting really hard not just me but the kids as well, we have followed all the advice on biting but to no avail.
I have the feeling that there may be a lack of consistency in response to her biting. Have you gotten everyone in the house on the same page so that the response to biting is the same from everyone. Dogs do a great job in sussing out who is the soft touch and Missy may have that figured out.
Biting does go away. My boy, Francis, was a terrible biter until I started getting him soupbones and let him know that biting people was very wrong.