A source close to Lori Loughlin confirms the couple "has every reason to believe" their daughters could be targets of prosecutors

Lori Loughlin and her husband Mossimo Giannulli continue to deal with the legal fallout for their alleged involvement in the college admissions scandal — and the couple is willing to protect their daughters at all costs.

Last week, DailyMail.com first reported that one of the couple’s daughters — either Olivia Jade, 19, or Isabella Rose, 20 — was under criminal investigation in the case. Also last week, the Wall Street Journal reported that several students had received “target letters” from federal investigators who believed they might have been complicit in their parents’ alleged acts.

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A source close to Loughlin confirms the couple “has every reason to believe” their daughters could be targets of prosecution — and they are taking their daughters’ well-being into account as they proceed in the case.

“Lori will not do anything to put her daughters in harm’s way,” the source tells PEOPLE. “She is like a mama bear when it comes to the girls, and she will do whatever she has to do to protect them from prosecution, especially malicious prosecution. Her top priority in all of this is to protect her daughters.”

Image zoom Olivia Jade Giannulli, Lori Loughlin and Isabella Rose Giannulli Gabriel Olsen/Getty

“The prosecution could easily charge the daughters in an attempt to get them [Loughlin and Giannulli] to plead guilty,” the source says. “But investigators have not disclosed any information that they may or may not have that would implicate either one of the daughters.”

On March 12, the U.S. Attorney’s Office in Massachusetts announced it had charged 50 people, including Loughlin, in the cheating scandal. The actress, along with coaches, admissions counselors and parents were accused of such alleged crimes as falsifying SAT scores and lying about the athletic skills of their children.

Loughlin allegedly wanted her daughters to get into the University of Southern California so badly that she and Giannulli paid approximately $500,000 in bribes to falsely designate their daughters as recruits to the USC crew team — despite the fact that they did not participate in crew.

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The complaint alleged the couple devised a plan to “present their younger daughter, falsely, as a crew coxswain for the L.A. Marina Club team, and requested that the Giannullis’s send an ‘Action Picture,’ asking a few days later for a picture on the ‘erg’ — or rowing machine, which Giannulli did a few days later.”

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Earlier this month, both Loughlin, 54, and Giannulli, 55, pleaded not guilty to the charges they face: mail fraud and money laundering conspiracy. If convicted, they face up to 20 years in prison for each charge.

According to the source, the couple is worried that the prosecution could charge one or both of the girls in an attempt to get them to plead guilty. “They feel that they’re in the middle of a squeeze play right now,” says the source. “It’s very complex, legally. On one hand, they have pleaded not guilty to the offenses they are alleged to have committed. But on the other hand, they know that pleading guilty could put the matter behind the whole family.”

“They are under an enormous amount of pressure, and the idea that the girls could be prosecuted is distressing, as you can imagine,” the source continues. “That just makes the pressure worse.”

The source says Loughlin is reluctant to go to trial.

“It’s not in their best interest for this to go to trial, and Lori knows it,” the source told PEOPLE last week. “She will continue to make a good faith effort to put this case behind her, and she hopes the prosecutors will do the same.”