Is one obligated to fulfill a vow to slaughter a calf and distribute it to the poor immediately after the wife conceives, or should one wait until childbirth, especially given the current lack of sufficient funds?

The inquirer's vow is a conditional vow, which is disliked to initiate. However, since she has vowed to slaughter a calf for charity, she is obligated to fulfill it if the condition it was tied to occurs, as Allah Almighty says: (And let them fulfill their vows), and as the Prophet, peace and blessings be upon him, said: (Whoever vows to obey Allah, let him obey Him). Therefore, she is obligated to fulfill her vow by slaughtering a calf and distributing it to the poor and needy if her co-wife gives birth to a child. She is not obligated to do so before the condition upon which the vow was suspended occurs.