Which jazz standards artists would be good tonal models for a high, light voiced female? I love artists like Ella, Etta, Billie, and Sarah, but they just don't sound like me.

Great question! Some jazz singers with lighter voices (mezzos/sopranos) are Jane Monheit, Gretchen Parlato, Veronica Swift, and Esperanza Spalding. Also look into songs by Gershwin & Porter!