[nicepace]

Fleetwood Mac had two female songwriter/musicians. One of these two was also an instrumentalist (someone who plays an instrument, as opposed to a musician, which also includes singers). However, it's not true that this was unique. There were numerous all-women bands, including for example the Go-Gos, the Bangles and the Runaways, who had several female songwriters and instrumentalists.

But those bands were entirely comprised of women. What made Fleetwood Mac different is that they had these two women songwriters/musicians in a mixed-gender group. This configuration is extraordinarily rare in the history of rock music. Heart is probably the only other instance of more than one woman musician in a famous mixed-gender group. But Christine was playing an instrument, singing, and writing her own songs years before Heart ever recorded an album. She is the true pioneer of women having an equal role as a singer/songwriter/instrumentalist in a mixed-gender band.