Answer
This is discussed in section 26-4, the “twin paradox,” which is not a paradox at all.
Work Step by Step
If the woman astronaut had been traveling at ultrahigh speeds during her trip (speeds beyond today’s technology) she would have aged less than her son who remained behind. As discussed previously, the woman and son do not undergo identical accelerations: she had to accelerate to return to Earth, whereas he didn’t have to.