Jennifer Garner Photo by: Francis Specker / LandovJennifer Garner appreciates her fans – even when they ask the tough questions.

Asked, "When are you going to have another [child]?" during a break in filming This Side of Truth last Friday, the 36-year-old actress laughed off the unexpected query.

"Sometime," she replied. "I don't know. I have to think about that one."

Garner – who was in Lowell, Mass., shooting the flick (costarring Tina Fey and Ricky Gervais) – made sure to spend quality time with fans of all ages. But she paid special attention to her youngest admirers.

"I have to say hi to the girls," she said, heading over to sign autographs for a crowd. She made sure all the children got some face time.

Ben Affleck's other half asked one little girl, "Are you a swimmer?" before revealing, "I was a swimmer when I was your age."

Other young fans asked about daughter Violet, 2. "She's good," replied Garner, who fended off compliments about her appearance with some good-natured modesty. She joked to one admirer: "That's what five hours of hair and makeup will do for you!"