"Ohh..." said Jon's mother. "Karyn? I... I'm sorry. It all got to me. You... OW! say we need a wish, right?"
"Yes, you and Jon need it badly." Karyn pushed the stone into Jane's hand.
"I wish that... that the 30 minute wait was only once per person, and..."
"The pregnancy, and the marriage!" said Karyn.
"And that we're not as pregnant as this and we're not wives to the same man." Then Jane fainted again. And Karyn found herself compelled to look away.
When Karyn looked back she saw that Jane was no longer fainted. There were two identical-looking babies, each with a little bit of blonde hair, one held by Jon and sucking at Jon's breast (which was exposed), and one held by Jane and sucking at hers. Jon was looking at the baby dumbfounded while it drained him of milk. Jane seemed much more familiar with the concept.
"I didn't mean..." said Jane. "But it looks like I'm a new mother again. And Jon is a mother too." Then she realized she didn't know what the other part of the wish did. It couldn't have reversed the other wish and made them single mothers again, but what did it do? Since the 30 minute limit was once per person and she had made a wish 30 minutes ago, she should be able to use the stone normally. So... "I wish I knew what happened when I wished we're not wives to the same man."