The attacker had been with Durham Women since July 2023 and joined United's fellow Women's Championship side following a prolific spell in the USA with Western Illinois University and Tormenta FC.
Throughout 2022, her final season with the latter, Andrews was named the first USL W League Golden Boot winner with 16 goals scored in ten games played during the 2022 regular season. That form came after scoring 34 goals across her time with Western Illinois University.
Magpies manager Becky Langley described Amy as "an exciting, raw talent" as she bolsters United's forward line.