Relative Strangers (1999)

Irishwoman Maureen, who lives in Germany, is happily married. Or so she thinks. When her husband dies, she finds out that not only had he debts, he was also a bigamist who had a second wife and family in Ireland. Shocked and angry, she travels there to meet the other family--and learns that they have their own troubles, the worst being that the other woman's young son is suffering from leukemia and urgently needs a suitable bone-marrow donor.