Mrs Connolly' is a non-canonical character, created for the 2022 miniseries Why Didn't They Ask Evans?, an adaptation of the Agatha Christie novel of the same name. She is a cook at Merroway Court.
Spoiler warning: A spoiler is announced! The following section contains details about the plot of Why Didn't They Ask Evans?.
Mrs Connolly offers Bobby a slice of lemon cake and, mollified by his compliments about her age, she supplies him with information about the frequent visits of the deceased Mr Savage.
Spoilers end here.