Mask of Fortune — Sally James

Dermot, Earl of Heronforth, reluctantly accepts the obligation of his dead brother to bear-lead young Bobby Blain around Town. But Bobby turns out to be Roberta, not at all what he expected. Bobby, already courted by two suitors at home, needs to be in London to attempt to clear her father's name of cheating at cards. Her discoveries lead to a kidnapping and a daring pursuit.