Will a person go to Hell, if she has had sexual intercourse with her husband and did not do Ghusul out of laziness?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Not having a Ghusul (ritual bath) after sexual defilement out of laziness until the time of the prayer has expired is one of the major great sins and whoever does so deserves Hellfire, and this act could even lead to disbelief in Allaah, because the prayer is one the greatest pillars of Islam after the two testimonies of faith. The Prophet said: "Between the man and disbelief is abandoning the prayer (obligatory prayer)." The prayer of a person who is sexually defiled is not accepted until he purifies himself. Allaah says (interpretation of meaning): {If you are in a state of Janaaba (sexual defilement) purify yourselves (bathe your whole body)}[5:6]. The Prophet said: "The prayer is not accepted without purification." [Muslim] Therefore, whoever was lazy in purifying himself after sexual defilement until the time of the prayer is over has to repent to Allaah and seek his forgiveness, and should have a Ghusul. The Prophet said: "There are 5 things whoever does them while believing in Allaah will enter Paradise…..and he fulfils the trust." So Abu Ad-Dardaa' the narrator of this narration was asked: 'And what is fulfilling the trust?" He replied: "It is to have a Ghusul after sexual defilement.' [Abu Daawood]. So having a Ghusul after sexual defilement is a trust that Allaah has entrusted us with and we will be accounted for it on the Day of Judgement. But if one delays having a bath but not until the time of the prayer is expired, then he is not sinful.

Allaah knows best.