She was a witch, and the source of her power was an object called The Mystical Mirror. For centuries, she stayed young and beautiful. She did this by hypnotizing her victims and getting them to drink special potions. The potions transformed her victims, which were beautiful young women into dogs. When she would find three victims at a time she would have a sacrificial ritual, and kill them to stay young and beautiful.
Her newest client Cindy soon found out her secret when seeing how old she really looked in all of her paintings and pictures in the reflection of her compact mirror. Because mirrors never lie and always reveal the true age.
Soon Ms. Valenti had captured and turned three victim into dogs, Tannis, Vicki and Laurel. She was about to perform a ritual, getting ready to sacrifice them. Possibly she would eat their tongues or drink their blood after killing them, how it was done was not explained.
Cindy interrupts the ritual, and grabs her mystical mirror. She threatens to smash her mirror if they're weren't all freed and changed back to normal. Ms. Valenti tried to put Cindy under her power and convince her to look at the mirror, to fall under her power as well.
However Cindy's emotions were too strong and she was able to resist. Then she smashed the mystical mirror. Therefore she rapidly began ageing away. First to an elderly woman. Then she died of old age and turnd into skeleton, then turned into nothing but dust.