The 'Fashion Star' mentor gave birth to her first daughter Maxwell Drew on May 1 and signed a USD 4 million contract with weight-loss brand Weight Watchers to become a representative for them, reported Contactmusic.
"She understands it's a process. (She is) working very hard and she's excited," a source said.
Earlier, Simpson had denied that there is a deadline for her to lose her baby weight and a representative for the company backed up her claim recently.