Is it permissible to give a portion of the vowed amount to the needy nephew (sister's son) instead of the nephew (brother's son) who was specified in the original vow, after Allah had granted salvation from the accident?

Whoever makes a vow to Allah Almighty to perform an act of devotion must fulfill it in the manner he vowed, as the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him; and whoever vows to disobey Allah, let him not disobey Him."