England back Kildunne's accolade comes off the back of a year that also saw her represent Team GB at the 2024 Paris Olympics, where they finished seventh.
She beat Red Roses team-mate Alex Matthews to the award, as well as France's Pauline Bourdon-Sansus and Canada's Alex Tessier.
In the last 12 months the Harlequins back has become one of England's most recognisable women's rugby players having also moved into fashion design, photography, and launched her own podcast with fellow Red Rose Jess Breach.