To Allen Herskowitz
I take it that since your mother was a child in 1930, that she and any siblings are no longer alive. Perhaps there are other relatives who might know something about the three children.
As for no one talking about the children - if there was some unpleasantness involved with this situation, it may have been something the family did not want to discuss.
I have the opposite situation to you - the disappearing relative. A sister of my father's was listed in a family tree from 1986 as being deceased. I never heard anyone speak of her, ever. I thought she had died back in the 1940s, since she was listed by my grandparents as being an invalid in the 1940 census. However, she was very much alive in 1986 - in a state institution where she had been sent around 1946-47.. And where she died in 1989, and where she is buried. This all came out on Ancestry.com, a complete shock to me and my brother. I think she may have been mentally retarded, but don't know for sure.
That is the joy and the dilemma of delving into one's family history - learning so much about one's forebears, but also learning about some difficult or disturbing situations.
Lock/Lak/Lok and Kalon in Zagare/Joniskis, Lithuania
Olitsky in Alytus, Suwalki, Poland/Lithuania
Gutman/Goodman in Czestochowa, Poland
Lavine in Trenton, New Jersey and Lida/Minsk gub., Belarus