The 45-year-old actress is the mother of three-month-old Louis Bardo Bullock - whom she adopted in January but chose to keep secret until after the Oscars in March.
Speaking about her son, who has been living with her since January, Sandra told People magazine: "It`s like he`s always been a part of our lives. He`s perfect, I can`t even describe him in any other way."
The `Blind Side` star has also started divorce proceedings against her husband Jesse James - who is alleged to have had multiple affairs while they were married.
Tattoo model Michelle `Bombshell` McGee went public with her 11-month affair just 10 days after Sandra won the Best Actress Oscar.
Speaking about the legal separation, she said: "I`m sad and I`m scared."
Although Sandra and Jesse started the adoption process four years ago together, the Hollywood beauty will now be the sole guardian of Louis - who was born in New Orleans.
The tot is named after late singer Louis Armstrong, who was born in New Orleans, because Sandra had his hit `What a Wonderful World` in her head when she first laid eyes on him.
It was reported last week, the actress was getting ready to start divorce proceedings against the `Monster Garage` host.
A source said: "It`s over between Sandra and Jesse. For a while, it looked like she was going to forgive him, but not now. Way too much has happened and after spending time alone, Sandra has realised that she deserves better. It`s not going to be easy but she`s an amazingly strong lady."