The Part of Spirit is calculated from the natal ascendant, plus the sun, minus the moon.  According to ancient Greek astrologers, the Part of Spirit (Greek: daimon) literally means that which distributes, or that which is distributed. Daimones were the ancestral spirits who watched over their descendants, the UNIX Operating System took that idea for long-running background processes  that answers  service requests and called them daemons.

When the Arabs conquered Ancient Greece, they renamed the “faces” to decans and daemons to genii, keeping the idea of the guardian spirits who are sparks of divinity present in all intelligent beings, whether good or ill.

Using the chart of singer-songwriter, Karen Carpenter, we see that her Part of Spirit, is 24 Capricorn in the Eighth House and suggests that despite that ethereal voice, Venus in Aquarius, she was too earth-bound and concerned with her self-image to get out of the anorexic web she had weaved and semi-sextile Jupiter and Mercury, the more acclaim she received the stronger this demon grew.

It was a great loss when she died of anorexia nervosa  (an eating disorder) on February 4, 1983.  Here is a fan site devoted to the brother-sister act.