She’s the mother of Fujino Asagami.
Miyuki was married to Hanefune Asakami of the Asakami family. They had a child, Fujino Asagami. Around the time Fujino was twelve, the family went bankrupt. Miyuki married into the branch Asagami family, her second husband Kouzou Asagami marrying her for the assets and land of the main family.
(Source: TYPE-MOON Wiki)
