Little is known about this woman, the one who actually married Edward Oak. Her marraige to Ed had one soul purpose... to produce a child to take over for her one her 'business' began. Even before she married the Professor, she had been planning this as she formed Team Rocket. She was, after all, the origanal founder.
She never felt any real connection to the family, especially not to that of her false son, Geoffrey. In actuality, she was disgusted by the Professor, and left as soon as Giovanni had been born.
After that, she wasn't heard from until several years later, when she called for an adualt Gio to work for the Rockets...