A proverb pointing out that close relatives of skilled professionals are often deprived of those services.
a barber's brother shaves with a bottle / cobbler's children go barefoot
watu wa karibu wanasahaulika
"Hana nguo nzuri ingawa kaka yake ni fundi nguo, maana nduguye kinyozi hunyoa kwa chupa."
Translation: He has no fine clothes though his brother is a tailor, because a barber's brother shaves with a bottle.