Christine Bolden, 26, of Muskegon was declared brain dead March 6 days after she collapsed while walking out of a Grand Rapids building with her 3-year-old son and boyfriend, The Grand Rapids Press reported.
Two brain aneurysms burst, apparently as a result of stress from pregnancy on a possible pre-existing health condition, doctors told Bolden's relatives.
While on life support, Bolden carried her twins until their birth by Caesarean section April 5.
The boys -- Bolden had chosen their names, Nicholas and Alexander -- remain in the hospital after their premature birth at 25 weeks.
Nicholas Maybanks-Bolden weighed only 1 pound, 9 ounces at birth; his brother, Alexander, 1 pound, 4 ounces, and family members say they expect the twins to remain at Helen DeVos Children's Hospital for months.
Vance Terrell, Christine's brother, said he longs for the day the babies can leave the hospital.
"I can't wait to be able to touch them and pick them up and tell them all about their mother and give them so much love," he said. "They're so precious."
Lytro unveils camera that can focus a photo after shooting it
Yosemite climber falls 30 feet, suffers major injuries