The sumo wrestler's attendant prepared a towel and water.
She works as a personal assistant for a famous singer.
随員 is used for official members of a diplomat's or dignitary's entourage, while 付き人 is a more general term for any personal attendant, such as one for a celebrity.
Standard spelling; common in news and general use.
Abbreviated spelling, less common but still encountered.
Compound of 付き (つき, 'attached to') + 人 (ひと, 'person'), with rendaku voicing of ひと to びと. Literally 'a person who is attached to someone'.