Is paying a portion of the vow's amount to the needy mother-in-law and sister-in-law considered a fulfillment of the vow taken by the husband?

If the woman who made the vow intended to disburse her vow to a specific entity, it must be disbursed to that entity. If she did not specify an entity, it should be given to the poor. It is permissible to give from the vow to the husband's mother and sister if they are poor. There is no harm in taking money from the vow from the husband with his consent and willingness. Vowing is disliked and does not change Allah's decree. The Prophet, peace and blessings be upon him, said: "Indeed, a vow brings no good; it merely extracts from the miser."