What is the ruling on a woman who sometimes misses prayers and delays ritual purification after intercourse out of remorse for her actions, and fears that her repentance may not be accepted?

Prayer is the greatest pillar of Islam after the two Shahadas, and whoever abandons it is a disbeliever, outside the fold of Islam. Therefore, a Muslim woman should not expose herself to disbelief due to the hardship of ghusl. Rather, she must repent and be diligent in prayer. Allah loves those who repent and forgives all sins for those who repent and turn to Him.