"She's so happy," the legendary songwriter and producer gushed during the ASCAP Rhythm and Soul Awards where he and musical partner Terry Lewis were honored in Beverly Hills, California, on Thursday.
Jackson has been working with Jam and Lewis since the '80s. The duo is responsible for her iconic Control album, along with various hits including, "When I Think Of You," "Miss You Much," and "Again."
Though Jackson has been living in London, she usually reaches out to Jam via text message or FaceTime, so that he can have a chat with his "nephew."
"I get FaceTime [calls] at like two in the morning, usually when I'm wrapping up in the studio," he shared. "It's always just Isa [on FaceTime], she's in the background somewhere. He's the cutest baby in the history of babies."
Despite enjoying her time away from the spotlight Jackson is "excited to go back to her day job," of performing and recording music, Jam tells ET.
And becoming a mother is sure to provide some creative inspiration for the GRAMMY winner.
"I told her that when you have a baby, it's going to be a whole different inspiration for you," he shared."A whole different reservoir of creativity, of cadence, of love, and all these things that have always been with you but it doesn't really come out until [you become a parent]. She's recognizing that."
In May, a source close to Jackson, who split from husband Wissam Al Mana not long after Eissa's birth, revealed to ET that she wants to bring her son on tour.
"She will be in court to flesh out the dissolution of her marriage," the source said at the time. "Touring with baby Eissa could be a possible problem but she's hoping it's not."
Although she's already dropped 50 pounds of baby weight, Jackson plans to get in even better shape before she hits the road.
"She'll be coming out full force and unrestricted," the source added. "Janet will begin rigorously dieting. She wants to look her best for herself and her fans."