Dorothy Paget was the most famous Woman gambler of all time, outside Bodica taking on the Romans
She single handed started the now William Hill empire through her losses. Known for her late night partying she would awake the next day after racing was over. Regardless, William Hill still took her four figure bets even though she owned a string of horses to become a somewhat mythical fearless bookmaker. Truth is he struck gold with her and he was as bad at taking bets as the rest, today I'm allowed €2.68 on a hoss
Her biography is well worth reading if only to take in the us and them of the times.