Question on the film the orphan?

i watched a couple of scenes including the ending..and like the mom hates it when the kids play by the water....is there a specific reason to why she hates it that much or is it because shes scared the ice will break?? like that one scene esther was pulling max on the sled on the water and the mom came out of the house screaming in terror "GET OUT OF THE WATER..U NOE UR NOT SUPOSE TO PLAY BY THE WATER'' nd ya just wants to noe wats thats all about