A gift or 'Hiba" has been defined under the Mohammedan Law as a transfer of property made immediately and without consideration by one person to another and accepted by or on behalf of the latter.
The gift is in the nature of contract where there must by a tender of property, acceptance of the property by the donee and delivery of possession of the property.
Bequeathing property by a Will will be restricted to only one third of the entire property by the testator whereas there is no such restriction in the case of a gift (hiba). The essential condition is that if there is no delivery of possession, the gift is invalid even if it is registered
Normally a gift once made is irrevocable because a gift is an absolute transfer of property by the donor to the donee made without consideration. . A gift, however, is always revocable before delivery of possession for the simple reason that, before delivery, a gift is incomplete. Even after delivery of possession, a Mohammedan gift can be revoked by a decree of court under certain cases.
Only the donor can revoke the gift and not by any of his heirs. A revocation is effected only by a decree of a competent court after delivery of possession is made, and until such decree is passed, the donee is entitled to the thing given.
Thus from the above it can be construed that the sisters cannot claim a share in the property once the rem was a delivery of possession of the property subsequent to the gif deedexecued and registered in your favor. Let them fight it out in the court, it will not be maintainable and sustain.