Responsa על בבא קמא 237:6

(3) As an apostate, L forfeits her rights as an heir, even though she has the power to transmit her property to her Jewish heirs. Although it is not known whether L apostatized after her parents were killed, it is legally assumed that she has apostatized after their death. Nonetheless, L's heirs cannot acquire L's property and rights of an heir, during the latter's lifetime, since the above mentioned assumption does not devolve for the benefit of her heirs. The disputed property should be retained by A, and C's heirs, inasmuch as they are in possession of this property.