Mallette, 37, told People magazine her parenting style changed once the singer reached his 18th birthday in 2012.
"His life was my life and now I've had to let him go a little bit and let him be independent. It is hard to not be able to control everything that your adult child does," she said.
She said she texts or calls her son every day while he's on a world tour.
"I definitely want to know everything that he is doing and what he is going through so I try to talk to him as much as he'll let me. I mean, he's on tour and being pulled in a million different directions but we talk as much as he is able," she said.
Mallette said she's not oblivious to some of Bieber's behavior, but she's also not prepared to discuss that with strangers, People reported.
"A lot of people might think that I have my head in the sand or that I am oblivious to the things my son is doing," she said. "I know who my son is and I don't always agree with every single thing that he does but I don't necessarily have to address that with everyone else. He's my son and I have to respect he is not going to want me going around being 'that mom' talking about his behavior."