Frost, the daughter of Grand National-winning jockey Jimmy Frost, won the Foxhunter Challenge Cup at Cheltenham on Pacha Du Polder last spring and has enjoyed a tremendous first winter as a professional.
Her run of big-race successes include the Grade One Kauto Star Novices' Chase on Black Corton and the Betfred Classic Chase on Milansbar.
Frost gained her latest notable triumph on the always-prominent Marracudja by a length and a quarter from Baby King, for her boss Paul Nicholls.
Speaking from Sandown, Nicholls was full of praise for the young rider.
"He is a quirky old horse and he was a bit on and off. I was a bit worried it rained a bit too much, but she gave him a good ride and he won nicely," he said.
"I thought her 5lb claim might be handy today, but that was the last one and she is down to 3lb now.
"She is great. You have to be sensible what she rides and get her riding the right horses and using the claim sensibly. I don't want her riding four or five every day. If we just look after her and pick and choose the rides at the weekend, she will keep riding winners and do well.
"He wouldn't be good enough for the Grand Annual and he probably wants two and a half miles. He is probably the sort of horse you would run over two and a half at Ayr."