Bless Me Father (1978) (S1 Ep5)

Ep 5: Father and Mother. Father Duddleswell accidently damages a saintly portrait of the nun that founded St Jude's orphanage when up in the attic and discovers that there may be a valuable painting underneath. However, no sooner has he discovered this than the formiddable Mother Stephen hears of it and stakes a claim of her own for the portrait...

Starring Arthur Lowe, Daniel Albineri, Gabrielle Daye and Patrick McAlinney, with appearances by Derek Francis and Sheila Keith in her first appearance as the formiddable Mother Stephen.