Penelope (usually called Penny) is a early-mid 20s Appaloosa/draught cross mare and the only daughter of Biscuit and Rooster. She enjoys an incestuous relationship with her entire immediate family despite also dating Silver.
Penny masturbates to Preston and Biscuit when they have sex, but is jealous and wants Preston to herself. The rest of their family is unaware that Biscuit and Penny also have sex. Penny is secretly deeply in love with her father.
Silver knows she has sex with Preston and is against it, but doesn’t do anything about it.