We’d like to clarify that the ruling regarding this issue depends on the question whether performing Hajj is obligatory immediately as soon as one becomes financially and physically able to perform it or it can be delayed for a most proper time.
Actually, this is a controversial issue among Muslim jurists. A group of Muslim scholars maintain that Hajj must be performed as soon as one is able to, and delaying it is counted as a sin. Another opinion views that it can be delayed with the intention of performing it soon.
So, if one acts according to the opinion that Hajj must be performed immediately, then Hajj takes precedence over marrying son or daughter. But if one acts according to the opinion which view that Hajj can be delayed, then marrying son or daughter can take precedence.
Having clarified the above, you can act according to one of the above-mentioned opinions based on the state of a son or daughter with regard to marriage. If there is a good proposal for a daughter and there is fear that she may not find such a good proposal, then one can act according to the opinion that Hajj can be delayed. This applies also to the state of the son if he cannot control himself and there is fear that he may fall into sin.
However, if the daughter is still young and she may get better proposal or the son can control himself and there is no fear on him falling into sin, you can act according to the opinion that considers delaying Hajj is a sin.
Having stated the above, we ask Allah Almighty to help you perform Hajj and marry your sons and daughters and to grant you and your offspring happiness in this worldly life and in the Hereafter.