If mothers are forged through physical labor and ballerinas through decades of training, a woman who is both is a particular kind of force. That certainly seems to be the case for Isabella Boylston , a principal with American Ballet Theatre , who is due in June. “Becoming a mom is so abstract until you are one,” she tells me over the phone in late March. The 39-year-old had just finished lunch after spending the first part of the day teaching, a recent addition to her ABT work schedule that replaces the hours she would have spent rehearsing for the Spring 2026 season. “I still feel like I can’t totally conceptualize what it’s going to be like, but I definitely want to continue dancing for many years," she says. Like any woman, there’s a see-how-you-feel element to when she’ll be back to firing on all cylinders, but there’s no doubt in her mind that she’ll return to the stage.…