Lori Loughlin Source: ‘USC Became Her Obsession’

For Lori Loughlin’s daughters’ college education, the Fuller House star had only one school in mind: the University of Southern California.

“Lori was always very impressed when she met a parent who got their child into a prestigious school,” a family source tells PEOPLE in this week’s issue.

“USC became Lori’s obsession,” the family source says about Loughlin, who is at the center of the nationwide college admissions scandal. “This was the school she wanted her girls to attend.”

RELATED: How Lori Loughlin Met the Ringleader of College Admissions Cheating Scandal: ‘Bribes and Lies’

Loughlin’s desire for Olivia Jade, 19, and Isabella Rose, 20, to attend USC was so deep that she and husband Mossimo Giannulli allegedly paid $500,000 to admissions consultant William “Rick” Singer to help falsely designate the couple’s daughters as recruits to the USC crew team, despite the fact that neither ever participated in the sport.

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Last month, the U.S. Attorney’s Office in Massachusetts announced on March 12 that it had charged 50 people, including Loughlin and fellow actress Felicity Huffman, in the cheating scandal. The two actresses, 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.

On Monday, Loughlin and Giannulli pleaded not guilty to both 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 family source, Loughlin’s desire to have her daughters attend the elite L.A.-based university stemmed from her need to “keep up” with those in her social circle.

RELATED: Lori Loughlin Was ‘Fixated on Getting Her Girls into USC,’ Source Says: ‘It Was a Status Thing’

“For most people that they socialize with, schools are very important. It’s very much a status thing,” says the family source. “Parents brag about their children’s schools all the time. So many of the schools are almost impossible to get into.”

“From the outside, Lori’s family looks perfect,” the family source says.

But despite Loughlin and Giannulli living in one of the wealthiest communities in the United States and each having successful and lucrative careers, the actress still felt the pressure to maintain a specific image.

“They are wealthy and successful, live in a gorgeous Bel Air mansion and their daughters are beautiful. But they are also surrounded by families who are even wealthier,” says the family source. “Although it’s hard to understand, these are the families Lori was trying to keep up with.”