Are the doubts and obsessions regarding the purity of a sister afflicted with urinary incontinence, her belongings, her sitting places, and the places and things she touches, based on truth, or are they merely baseless whispers [waswas]?

The whispers of Shaytan (waswasa) have reached a great extent, and everything mentioned is based on them. The fundamental principle regarding things is purity. So, if one doubts the impurity of something, it remains pure, especially since the sister is a Muslim, an adult, and avoids impurity. These whispers must be abandoned, and people should not be informed of the sister's "illness" under the pretext of avoiding impurity, as this is a breach of the sanctity of a believer.