Is my grandmother, who suffers from involuntary urinary leakage during prayer and cannot control it, treated the same as someone with urinary incontinence, such that she is not required to purify her clothes for each prayer and can continue with her ablution and prayer despite the leakage, or must she repeat ablution and purification every time?

One who suffers from urinary incontinence is not required to repeat ablution or prayer. She should wash the affected area, protect herself with a cloth, and perform ablution for each prayer after its time has begun. The involuntary discharge of urine after ablution or during prayer does not harm her, and her prayer is valid. As for clothing, if it is soiled with urine, it should be purified or changed if possible; otherwise, there is no harm in praying in it.