Friends of Sandra Bullock say the actress cries every day over her fear of losing custody of Sunny, her husband Jesse James’ daughter.

Last January, Sandra, 45, and Jesse were granted temporary custody of the 5-year-old when Jesse’s ex, former porn star Janine Lindemulder, was sentenced to six months in jail for tax evasion. Now, Janine — who has appeared in more than 100 adult films — has been released from prison and is seeking custody of Sunny.

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“Sandra’s so upset,’’ a friend tells BettyConfidential. ‘’She loves Sunny like she was her own and even lessened her workload in order to raise the little girl. Sometimes, Sunny even calls her Mommy. So Sandra is not giving up.’’

A worried Sandra and Jesse, 40, have written letters to the court requesting permanent guardianship of Sunny and have questioned Janine’s fitness as a parent because of concerns about her alleged drug use.

“I myself have stopped working like I used to in order to be here with Jesse and the kids because we are on constant high alert,’’ Sandra said. ‘’Never knowing what condition Janine will be in, and even more concerning the condition Sunny will be in. While in Janine’s care, sometimes Sunny is left alone during the day, while her mother is asleep from drug use. I know the term ‘stepmother’ carries many connotations, one of them being glorified babysitter. My commitment and responsibility to Sunny goes beyond that.’’

Sandra also defended her motives for wanting sole custody. “Janine has claimed many times that my desire to have Sunny was because I could not have children of my own. It couldn’t be further from the truth.”