Why didn't Joanne Whalley become a major film star after Willow?
It seems like she's more known for marrying Val Kilmer and siring his children than for her own acting career. Her most noteworthy role after Willow was probably as Scarlett O'Hara in the made-for-TV miniseries sequel to Gone with the Wind. She was also in The Man Who Knew Too Little with Bill Murray. And she was most recently on the Daredevil series as Sister Maggie.
https://www.tvovermind.com/whatever-happened-to-joanne-whalley/
https://stack.com.au/film-tv/whatever-happened-to-joanne-whalley/