Probate Records

When my husband's g-g-grandfather died in 1894, his widow, Margaret, went before the court to file for probate. In it, three children are listed by name. I know Margaret and her husband had more children, including my husband's g-grandfather. She named only those children who were still living with her and were dependent upon her, even though one was a daughter who was older than her brother (great-grandfather). She's not buried with her parents and brothers, so where is she? This calls for more searching to find Katherine.