At the time of his deportation, Jacob van Os was living with his wife's cousin, Mietje. Jacob had limited family in Belgium at the time of Esther's passing and I imagine that is how they ended up living together after the occupation.
Addition
At the time of his deportation, Jacob van Os was living with his wife's cousin, Mietje. Jacob had limited family in Belgium at the time of Esther's passing and I imagine that is how they ended up living together after the occupation.