Jesse James also wrote to the judge, blasting his ex-wife's lack of responsibility in paying her taxes and her lifestyle.
CLICK HERE to read the full text of James' letter.
"I believe that Janine should not be shown any leniency in her sentence," he wrote.
It's an interesting battle for the couple to wage. Before marrying James, Bullock, now 45, never expressed interest in becoming a mom, telling People magazine in 2005, "If I did have kids my entire life would shift. I would no longer act or be in magazines."
But now it seems fame and fortune aren't enough. In March, Bullock hinted in an interview with InStyle magazine that she regretted not having had children."If I waited too long, it's because we were supposed to do other things," Bullock told the magazine. "If it is just too late ... there are millions of children on this planet that I would be honored to call my own."
"She's been very frank about the fact that she chose her career rather than having children," said Albert Lee, Us Weekly's deputy news editor. "She's talked about how her mother always taught her to choose career over family. In that respect, she was certainly successful. She's one of the few women who can earn an eight-figure salary per movie, especially at that age."
According to Parade magazine's latest issue and court documents related to the custody case, Bullock has become close to James' three children from previous marriages, particularly with his 5-year-old daughter who is at the center of the custody dispute. Bullock tells Parade that she can't imagine life without the little girl.
"The universe put this in our lap," Bullock said. "I seemed to have stepped in right when I needed to be there. I now know that anything sweet, really sweet, that I have was nothing that I planned. If you don't have kids and animals, you don't truly know what real life is about."
But Bullock's latest role as a stepmother embroiled in a custody fight with James' ex-wife has been anything but sweet.
Before tying the knot with Bullock in 2004, James was married to Lindemulder for one year. He left Lindemulder when she was seven months pregnant with their daughter, her lawyer, Ron Hoevet, told the Orange County Register. Hoevet represented Lindemulder when she was ordered to pay almost $300,000 in outstanding taxes last year and served the six-month prison term.
Lindemulder has since spent six months in a halfway house and, according to court documents obtained by ABC News, has rented a "low-end three bedroom home in a fairly undesirable neighborhood in Hollywood." Lindemulder stated that it is the best she could do "because of her poor credit" and an order stating "I am not allowed to work in the adult [entertainment] industry, which is all I've ever done for the past 23 years."
Experts say keeping custody could be an uphill battle for Lindemulder.
"She's a former porn star, she's a convicted felon, she's done custody time, she's up against huge star power," said Dana Cole, a Los Angeles attorney. "Ultimately, though, a judge has to look at the big picture and understand that the child has the right to know both parents.
"Bitter custody disputes are actually not that uncommon. They happen every day in the courts, and judges have to balance out the competing factors."