Sen. Kirsten Gillibrand isn't positive Hillary Clinton will run for president, but the woman who took Clinton's former New York Senate seat would like to think so.
"In my mind, she's definitely running," Gillibrand tells PEOPLE. "Anytime I've ever talked to her, I've offered every bit of help in the world and she's never said no."
For her part, Gillibrand, whose candid new book Off the Sidelines hits shelves Sept 9., doesn't have her eye on the presidency quite yet. She's perfectly content where she is at the moment.
"I have young kids," says the mom of two, when asked if she'd consider a bid for the White House. "I really like where I am."
"I don't know that I aspire to it," she adds. "It's a very different job. I feel like where I am, I can accomplish a lot."
It's her current job with the United States Senate that's provided the fodder for her insightful – and sometimes groan-worthy – memoir.
In Off the Sidelines, Gillibrand, 47, shares a sobering incident in the congressional gym, where an older, male colleague told her, "Good thing you're working out, because you wouldn't want to get porky!" On another occasion, she writes, after she dropped 50 lbs. one of her fellow Senate members approached her, squeezed her stomach, and said, "Don't lose too much weight now. I like my girls chubby!"
Gillibrand isn't especially offended by her coworkers' remarks. "It was all statements that were being made by men who were well into their 60s, 70s or 80s," she says. "They had no clue that those are inappropriate things to say to a pregnant woman or a woman who just had a baby or to women in general."
For more on Sen. Gillibrand, including an excerpt from her new book Off the Sidelines, pick up a copy of this week's issue of PEOPLE, on newsstands Friday