She was one of the top amateur golfers in the country during her high school years, and was ranked 4th by the AJGA in the class of 2019.

[1] In 2021, Castle won the U.S. Women's Amateur at Westchester Country Club in New York, becoming the first number 63 seed to lift the Robert Cox Trophy.

Plagued by a rib injury, she started despite doctors' recommendations, and opened the week with a seven-over-par 79 in the first round of stroke play.

[4] She earned a start at the 2021 Cognizant Founders Cup on the LPGA Tour where she did not make the cut.

She made her professional debut at the FireKeepers Casino Hotel Championship on the Epson Tour.