** nurse, TB sanitarium, search sib(s)

I have two siblings, one is a half-brother and the other may be a twin or a girl or another birth of either sex to another woman. This was very hush-hush in our family, and I am only going by what I overheard. My father, married to my mother, was at the TB sanitarium in Cresson, PA, for several years. He had a child (I'm pretty sure a male whose name may have been Koontz ((sp))). I know nothing about the 2nd child who may or may not have been the child of this nurse. I am assuming she was not married, but I don't know for sure.