That is the sculptors initials..."Common Obverse (Heads) Design The obverse design of all coins in the American Women Quarters Program is by Laura Gardin Fraser, one of the most prolific female sculptors of the early 20th century, whose works span the art and numismatic worlds. Fraser’s design depicts a portrait of George Washington, which was originally composed and sculpted as a candidate to mark George Washington’s 200th birthday. Though recommended for the 1932 quarter, then-Treasury Secretary Mellon ultimately selected the familiar John Flannigan design. Inscriptions are “LIBERTY,” “IN GOD WE TRUST,” and “2022.”"

Either that or LGF. The back is Maya Angelou.