Adele was Sylvia Tilly's grandmother.
In 3189, Tilly commented to Michael Burnham that her "Granna Adele" always used to say "until you've flown a starship into a flaming nebula, and gotten everyone out alive, you haven't lived." (DIS: "Su'Kal")
This character was only mentioned in dialogue.
It was not indicated whether Adele was a maternal or paternal relative to Tilly, and thus, may be the same grandmother as was mentioned in "Far From Home".
In the novel The Way to the Stars, Adèle is named as Tilly's grandmother on her mother's side.