But while her grandfather Herman Milchman was one of the founders of the company, and her mother and father took over the business in the 1980s, Ms. Baltes chose a different path — accounting. Half a dozen years ago, when her parents wanted to retire and pass the baton to her, Ms. Baltes’s response was quick and to the point: No way.

“I don’t know how they got me,” she said.

She now supervises a staff of 40, and almost half of them women. “I’m all about girl power,” Ms. Baltes said.

Not everyone got the memo. When she started at the company and would order her drivers to get going with deliveries, “they looked at me like I had two heads,” Ms. Baltes said. “I had to be tough.”

Then there was a lunch with, among others, the general contracting team for a large developer. Ms. Baltes had been asked to prepare a quote for some equipment and was told “the guys wanted to meet me,” she said. A casual lunch was set up, and over burgers, Ms. Baltes got a grilling.

“Were you a manicurist or a hairdresser before you got this gig?” the men asked. “And who did you have to sleep with to get it?”

“I said, ‘You guys are idiots. A manicurist? Look how bad my nails are. Look how bad my roots are,’” she recalled. “I made a joke. I said that my grandfather slept with my grandmother.”

But sometimes being a woman is a bit of an advantage. “When my competitors and I are talking about our products, and there are 12 men and one me, and when I make my follow-up phone call, potential customers will remember me,” Ms. Baltes said. “And that’s important.”