Rocket From Infinity by Lester del Ray. I was doing a Google search and wound up with a match on Google Books.
Then the door at the rear of the hall opened and Pete turned with the rest and saw three people enter.
"Well, speak of the devil," Jerry Sells said. "Or at least, the devil's wife. What do you want here, Rachel?"
The older woman in the trio was a plump, motherly looking person with mild blue eyes and an open, disarming manner. "Why, Jerry Sells," she accused. "That's a terrible thing to say about a body."
The context is not that someone has been accused of piracy, but that rather that someone claimed to have been jumped by pirates, and a general discussion of "claim jumping" on asteroid mining, partly that Rachel has been doing it.
Summary from Goodreads
When Pete Mason's father is badly hurt in a space mining accident, eighteen-year-old Pete suspects that the injury was no accident -- that it was caused by his family's rivals, Rachel Barry and her children. Even so, when Pete receives an urgent call for help from Jane, Rachel's oldest daughter, he risks his life to save her, only to find that Jane's uncle has taken advantage of the opportunity to jump Pete's new mining claim. Pete is furious; he refuses to listen to Jane's story of a mysterious derelict rocket that appeared from nowhere to threaten her life.
But the two young people meet again, quite by accident, when they are both caught in the middle of a terrifying situation from which there seems to be no escape. The surprising explanation of the derelict rocketship, and the growing relationship between Pete and Jane, provides a fast-paced, thrilling climax to this beautifully written science fiction adventure.