Is it permissible to perform tayammum when ghusl is not possible due to the mother's unawareness of nocturnal emission and the delay of prayer for days?

It is not permissible to perform tayammum (dry ablution) as a substitute for ghusl (ritual bath) due to a wet dream. Rather, ghusl is obligatory if the emission of semen is confirmed. It is not necessary to change clothes because semen is pure. Deliberately delaying the prayer until its time expires is among the major sins. However, if semen is emitted while awake without desire (due to illness or the like), there is a difference of opinion among scholars regarding the obligation of ghusl.