Ukraine to Boston, appx 1903 - sister of Leib Mill

My great-grandfather, Louis (Leib Hesch) Mill, from Ukraine, who settled in Boston 1901-1903, where the family name evolved to Mills, had a sister who married a man named
Kantor (or Cantor - unsure of spelling).I don't know
anymore than that about that branch.Am trying to trace
the family tree - hoping that someone from another branch may know the names of the Mill siblings parents (where they were from, etc).
Louis was married to Sadie Kreem & they had 10 children.
Another sister branched off into the Knarger family.