The WNBA "requires players to be at least 22 (Anna in 2022), to have completed their college eligibility (Anna in 2023), to have graduated from a four-year college (Anna in 2023) or to be four years removed from high school". (Anna in 2023) Since the WNBA draft is currently held in April, before most U.S. colleges and universities have ended their academic years, the league considers anyone scheduled to graduate in the 3 months after the draft to be a "graduate" for draft purposes. The current rules for draft eligibility have been in place since at least 2014. (Anna probably in 2023, but I won’t make assumptions.)
The specifics of this rule differ in several ways from those used by the NBA for its draft.
Both drafts make a distinction between U.S. and "international" players. [...] On the other hand, the WNBA defines an "international player" as "any person born and residing outside the United States who participates in the game of basketball as an amateur or professional" (emphasis added), and who has never "exercised intercollegiate basketball eligibility" in the U.S.[4] This means that a prospective WNBA player who was born in the United States is treated as a U.S. player, regardless of where she was educated or trained in basketball. Likewise, the association also defines as an "international player" a prospect with non-U.S. nationality even if one of her parents is a natural-born American, unless she has enrolled in a U.S. postsecondary institution. (Anna has enrolled...)
A WNBA prospect who graduates from college while under the age limit can be eligible, but only if the calendar year of her college graduation is no earlier than the fourth after her high school graduation. (Not Anna...)
Moral of the story — Anna is draft eligible in 2022.