According to a Facebook page dedicated to the victims, their mother, Marina Krim, is pregnant.
Marina and Kevin Krim posted: "We are very happy to let you know that Marina is expecting a baby in the fall. Nessie can't wait to welcome her new baby brother. We are filled with many emotions as we look to the future, but the most important one is hope. We are very grateful to you all for your amazing support."
Krim's children, Lulu, 6, and Leo, 2, were stabbed to death in their apartment on the Upper West Side last fall.
Their nanny, 50-year-old Yoselyn Ortega, is charged with their murder.
The couple's middle child Nessie was not home.
Their new baby boy is due this fall.
The Leo and Lulu Fund's Facebook page is about a fund for arts education dedicated to the memory of the Krim's children.