Anna Justine Mahler (June 15, 1904-June 3, 1988) was an Austrian sculptor. Born in Vienna, Anna Mahler was the second child of the composer Gustav Mahler and his wife Alma Schindler.
Biography on Wikipedia: https://en.wikipedia.org/wiki/Anna_Mahler

Tower of Masks by Anna Mahler
1961 / Limestone / Height: 15 ft / University of California (UCLA)  Photo © Ewald Judt

Anna Mahler on Artnet: http://www.artnet.com/artists/anna-mahler/

Further reading:
https://artistscollectingsociety.org/members/anna-mahler/
https://mahlerfoundation.org/mahler/family-tree/generation-7/2-anna-justine-mahler-gucki-1904-1988/
https://stephenjones.blog/2020/11/18/anna-mahler/