I'm not familiar with Koralewski. But I do have some Ostrowski ancestors. (Grandmother Lesley, Great grandfather Edward and his father Anthony.
Anthony's wife Anna, I'm not sure of her maiden name...but I've got a hint in my Ancestry tree for an Anna "Anna Kozlowska".
I don't have a lot of contact with that side of my family...but I do believe there was some immigration from Poland.