This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
Tilly didn't believe that she and her mother got along very well, believing Siobhan didn't like "children touching her, needing things from her, or actually generally being around her." (DIS: "Choose to Live")
Sylvia started to say that her "mother always said...", before correcting herself: "my mother never really said anything to me unless she was criticizing my hair", when attempting to convey to Michael Burnham that she shouldn't be afraid to open the delivery of Philippa Georgiou's last will and testament. (DIS: "The Butcher's Knife Cares Not for the Lamb's Cry")
It was stated that Siobhan had more than one "posting", causing her and family to move locations, suggesting she was either a Starfleet officer or a member of another service organization.
In The Way to the Stars, Siobhan is portrayed as a rising member of the Federation Security Council, divorced from Tilly's father, a xenoarchaeologist in Starfleet.