She was about 20, and this was her most significant nudity. She did this about two years after her run on Little House on the Prairie.
Elsewhere in her career:
She exposed a prosthetic mangled nipple in a 2006 episode of Nip/Tuck
And she flashed a nipple for about a single frame, possibly accidentally, in a 2003 TV movie called Hollywood Wives: The New Generation. (I think that was 56-year-old Farrah Fawcetts’s last starring role.)
Would’ve liked to have seen those big fake boobs she used to have in a proper, sexy topless scene.