Proud grandma Marie Osmond exclusively shares with Closer all the highlights of her first month getting to know grandson Stephen Jr.

“Being a grandma is the best!” the 54-year-old excitedly tells Closer. “Can’t you see me jumping up and down with excitement? Did I mention it rocks?”

Marie tells the mag about the first time she met her grandson. “I just sat there holding the baby the whole time and taking in this miracle. I was looking at every little toe and finger,” she reveals. “It was one of those really wonderful, special moments.”

Marie’s grandson already has a circle of celebrity pals. There’s his famous great-uncle Donny, of course, and the co-hosts of "The Talk."

“Marie is a doting grandmother,” Sharon Osbourne shares, while Sheryl Underwood tells the mag, “Having Marie Osmond as your grandma; I bet [he’s] going to have everything. The baby could throw up on her and she’s going to keep singing ‘Paper Roses.’ I hope she has a lot more grandkids!”

According to Marie, the baby may even take part in the family business! “So far he cries in perfect pitch,” Marie jokes. “I’m just saying!”

The entertainer is also taking steps to stay healthy so she'll be able to keep up with him as he grows and is a spokeswoman for the weight-loss company Nutrisystem.

"Since joining Nutrisystem, my philosophy is different," she tells Closer. "I don't starve myself to be skinny. I eat to be healthy, I exercise to feel good and I sleep so I don't pass out."

FOR MORE, PICK UP THE NEW ISSUE OF CLOSER WEEKLY, ON NEWSSTANDS NOW.