But today we are talking about Sabrina or Sabrina Fair whose name is important to some degree in all three renditions. From the 1995 film:
Linus Larrabee: So, that really is a beautiful name. How did you get it?
Sabrina: My father's reading. It's in a poem.
Linus Larrabee: Oh?
Sabrina: "Sabrina fair, listen where thou art sitting under the glassy, cool, translucent wave, in twisted braids of lilies knitting the loose train of thy amber-dropping hair."
Linus Larrabee: [pause] So, your little poem - what does it mean?
Sabrina: It's the story of a water sprite who saved a virgin from a fate worse than death.
Linus Larrabee: And Sabrina's the virgin.
Sabrina: [quietly] Sabrina's the savior.
You can read the similar conversation in the original play here on pages 41-42. In that version, I learned that the poem was from John Milton's play, Comus. You can read an online version of Comus here or read about it on Wikipedia.
Sabrina, as a water sprite, is referenced frequently enough in literature beyond the Sabrina play/films that I decided to include the excerpt from Comus in Mermaid and Other Water Spirit Tales From Around the World since her semi-fame was brought about by the play. Alas, these days the name is more often associated with witches thanks to shows like Sabrina the Teenage Witch, but she was a princess and then a water sprite, not a witch in folklore.
Milton didn't invent the character, however. Sabrina—also known as Sabre, Severn, Hafren, Habrena—first appears in Geoffrey of Monmouth's Historia Regum Britanniae (c. 1136). A princess who drowned in the river Severn, she later became a goddess associated with the river.
I'm only going to include the first part of the excerpt since it is rather long overall. Most quotes only use the short Sabrina Fair sequence that appears in the play/films. But I am including the part previous to that which describes Sabrina to the audience.
SPIRIT: There is a gentle Nymph not far from hence,
That with moist curb sways the smooth Severn stream:
Sabrina is her name: a virgin pure;
Whilom she was the daughter of Locrine,
That had the sceptre from his father Brute.
She, guiltless damsel, flying the mad pursuit
Of her enraged stepdame, Guendolen,
Commended her fair innocence to the flood
That stayed her flight with his cross-flowing course.
The water-Nymphs, that in the bottom played,
Held up their pearled wrists, and took her in,
Bearing her straight to aged Nereus’ hall;
Who, piteous of her woes, reared her lank head,
And gave her to his daughters to imbathe
In nectared lavers strewed with asphodil,
And through the porch and inlet of each sense
Dropt in ambrosial oils, till she revived.
And underwent a quick immortal change,
Made Goddess of the river. Still she retains
Her maiden gentleness, and oft at eve
Visits the herds along with twilight meadows,
Helping all urchin blasts, and ill-luck signs
That the shrewd meddling Elf delights to make,
Which she with pretious vialed liquors heals:
For which the Shepherds, at their festivals,
Carol her goodness loud in rustic lays,
And throw sweet garland wreaths into her stream,
Of pansies, pinks, and gaudy daffadils.
And, as the old Swain said, she can unlock
The clasping charm, and thaw the numbing spell,
If she be right invoked in warbled song;
For maidenhood she loves, and will be swift
To aid a virgin, such as was herself,
In hard-besetting need. This will I try,
And add the power of some adjuring verse.
Song for Sabrina
Listen where thou art sitting
Under the glassy, cool, translucent wave,
In twisted braids of lilies knitting
The loose train of thy amber-dropping hair;
Listen for dear honour’s sake,
Goddess of the silver lake,
Listen and save!