The actress' play-or-pay contract stipulated she gets a six figure compensation deal should she be axed from a production, TMZ reported Monday.
Duff, who announced in early August she was expecting her first child with her NHL-player husband Mike Comrie, told the entertainment website, "I don't wanna give them any more press than they've already gotten off me ... I think [my] baby is a little bit more exciting."
A replacement has yet to be cast. Amanda Seyfried was approached to take over the role, but she declined, according to the website.
The remake was announced in early 2009, and Duff's casting was immediately derided by the original star, Faye Dunaway.
"Couldn't they at least cast a real actress?" the screen legend reportedly said when she learned the former "Lizzie McGuire" star would be filling her shoes.
Duff fired back at Dunaway, saying, "I think that my fans that are going to go see the movie don't even know who she is, so you know ... I think it was a little unnecessary but I might be mad if I looked like that now too."