What is the ruling regarding a wife who does not pray despite her husband's admonition, and she justifies this by her inability to perform ghusl after every state of janabah?

Abandoning prayer is a grave sin and one of the greatest destructive acts, worse than adultery, theft, drinking alcohol, and killing a soul, by consensus of Muslims. Some scholars even consider one who deliberately abandons it and lets its time expire to be a disbeliever.

The woman must repent, and her excuse is not acceptable. If she is able to perform ghusl, it is obligatory. If she is unable, she should perform tayammum and pray.

Her husband must encourage her to pray and employ all possible means, in accordance with the Almighty's saying: "O you who have believed, protect yourselves and your families from a Fire," and the Prophet’s (peace be upon him) saying: "Each of you is a guardian, and each of you is responsible for his subjects."