Is prayer obligatory for a disabled sister who cannot hear or speak, has difficulty walking, suffers from severe vision impairment, and does not understand what prayer is?

If a girl is mentally incapacitated, she is not obligated to pray, because intellect is the basis of religious accountability (taklif). However, if she is of sound mind, she must be taught how to pray and what other obligations are incumbent upon her, and how to perform them to the best of her ability using possible methods such as writing and signaling.

Sheikh Ibn Baz clarified that if a deaf-mute person reaches maturity with a sound intellect, they are accountable, and it is obligatory to teach them duties and prohibitions through writing or signaling. They must fear Allah to the best of their ability by performing obligations and avoiding prohibitions, and they should seek understanding in religion according to their capacity.

The rulings of the religion are taught to them through action; their guardian prays in front of them so they can understand, the prayer times are explained to them, and the creed, the pillars of Islam, and the rulings of prayer, ablution (wudu), ritual bath (ghusl), and other religious rulings are written for those who can read. If their intellect is ascertained by any means after reaching puberty, they become subject to the rulings of accountable individuals according to their knowledge and ability. However, if they are not of sound mind, there is no blame upon them, because the pen is lifted from the insane.