You could easily watch Carrie Fisher's performance in Charlie's Angels: Full Throttle and have no idea it was her. The film itself is a wonderful exercise in suspended belief, and so when the Sound of Music's "The Lonely Goatherd" starts playing in the background as the Angels investigate a nun-run orphanage (whilst also pretending to be nuns) you know that you're going to be in for a good time. The real treat is discovering that the Mother Superior is the one and only Carrie Fisher. Having also played a nun in Kevin Smith's Jay and Silent Bob Strike Back, she was excellently qualified for the role. More Baroness Schraeder than Fräulein Maria, Fisher is sublimely creepy as she tells the girls the brief origins of their old nemesis the Thin Man. Whilst she gives them the information they need, her use of a ruler to discipline the often out-of-line Dylan is brilliant, and demonstrates Fisher's excellent and under-appreciated comic timing. This, along with flashback scenes of the disturbing haircuts she gave to the Thin Man (and continues to provide for him), make us thoroughly entertained if slightly unnerved by Fisher's superior Mother Superior.
