One of the original Band Aids, Sapphire gets more screen time than any of her counterparts, aside from Penny Lane. When we first meet her, she has kind of a wild goth vibe going on—probably because she had just been hanging out with Black Sabbath. Of course, in Tempe, just before she runs into a wall, we see her rocking a cowboy hat, so we get the sense she's a pretty free spirit.
Sapphire delivers a few pieces of very important news throughout the movie. First, she happens to be the one who picks up the phone in Tempe when Elaine calls, trying to reach William. "Is this Mary Anne with the pot?" Sapphire asks. Elaine is not amused. She explains matter-of-factly that she is William's mother, and that she "knows what's going on."
Sapphire doesn't back down, though: she calmly tries to reassure a worried and frustrated Elaine. "You should be really proud of him," Sapphire says. "[…] He respects women, and he likes women, and let's just pause and appreciate a man like that. You created him out of thin air, and you raised him right, and we're all looking out for him." She pauses before signing off. "This is the maid speaking, by the way."
Sapphire is confident and self-assured, and she has no problem doing what Russell later fails to do: she holds her own against Elaine Miller, the most intimidating mother around.
At the end of the film, Sapphire has a crucial conversation with Russell. She gives him an update on Penny and explains that everybody knows what he did to William. Ultimately, she reminds Russell what it means to be a true fan—"to truly love some silly little piece of music, or some band, so much that it hurts"—and she reminds him that he deeply hurt two of his biggest ones. Sapphire is passionate and poised (when she wants to be), and she has no problem telling it like it is.