"The girls are with them all the time and behind them every step of the way," the source tells E! News. "They are supportive of their parents decision and want them to

"The girls are with them all the time and behind them every step of the way," the source tells E! News. "They are supportive of their parents decision and want them to be able to move on with their lives."

According to prosecutors, the YouTube star, 20, and her older sister, 21, were fraudulently admitted to the University of Southern California as purported athletic recruits. Lori and Mossimo are accused of conspiring with William "Rick" Singer to secure Olivia and Bella's admission through various payments to the private college.

As part of the plea agreement, Lori is expected to get two months in prison, a $150,000 fine and two years of supervised release with 100 hours of community service. Under the terms of Mossimo's plea agreement, he's agreed to a sentence, subject to the Court's approval, of five months in prison, a $250,000 fine and two years of supervised release with 250 hours of community service.

Their daughters have said little about the alleged crimes, but Olivia did wish Lori a Happy Mother's Day on Instagram this month.