The singer, 29, used to promote her sister's former show regularly on her Twitter ("Everyone watch my sis on melrose place tonight," she wrote Oct. 20).
But on Sunday, she changed her tune drastically. Jessica wrote: "CW catching up on MP.who writes this crap?i have had bad scripts to work with,but this? thank God my sister is amazing and got you some press."
According to the new issue of Us Weekly (on newsstands now), Ashlee, a veteran of TV's 7th Heaven, was canned because producers thought she couldn't act.
"They hired her because they needed a good name to help create buzz," a set insider told Us Weekly. "But she was embarrassingly bad. Producers cut her down as much as possible."
Seconds another source: "She's the worst actress, but nobody will tell her."
What's next for Ashlee?
Possibly more acting.
Us Weekly reports the mom of 11-month-old Bronx (dad is rocker Pete Wentz, 30) doesn't want to return to her songstress roots. "She's reading scripts. Acting is her focus now," a source tells Us Weekly. "If she had an album, she'd have to tour and be away from Bronx. She wants consistency."