Has a lady jockey ever won the Grand National?

The simple answer is no, at least, not yet. The first lady jockey to ride in the Grand National was Charlotte Brew, who failed to complete the course on her own horse, Barony Court, in 1977. The first lady jockey to complete the Grand National course was Geraldine Rees, on Cheers, in 1982 and although several other lady jockeys have done so subsequently few of them have threatened to win the world famous steeplechase. So far, those to have achieved the highest placings are Rosemary Henderson, on Fiddlers Pike, Carrie Ford, on Forest Gunner, and Bryony Frost, on Milansbar, who all finished fifth, in 1994, 2005 and 2018, respectively, and Katie Walsh, on Seabass, who finished third in 2012.