The woman was Ms. Alvarez, a county caseworker, and she held up a court order. Marcus explained quickly. Five years earlier, during the last months of his marriage, he had a short relationship with a woman named Renata, and he never knew she became pregnant. She raised Ivy alone in Tucson and told no one. When Renata died in a car accident last spring, her brother Curtis took the little girl in, and only then did Renata’s lawyer find a letter naming Marcus as the father.

A letter from Renata’s lawyer reached Marcus in June, and two supervised weekends followed at his house, where Curtis sat in the car while the twins played with Ivy. That is when my grandson drew his picture. Marcus asked the boys to keep it a surprise, because he was ashamed and feared how I would judge him. In September, Curtis cancelled every visit, and Ivy told Ms. Alvarez that her uncle locked her in her room and forgot to feed her. He wanted a $250,000 insurance trust.

That is why Marcus asked me to keep the twins. He flew out that Friday, turned off his phone, and sent his one text from a motel, because he did not want me worried until a judge had spoken. A rapid DNA test confirmed Ivy was his daughter, and on the eighth night an emergency judge granted him temporary custody. He drove straight to my house with her the next morning.

Curtis tried to argue, but two deputies arrived while Ms. Alvarez read the order, because he had followed Marcus across state lines against its terms. They walked him down the driveway in handcuffs. Ivy loosened her arms from my waist and asked whether I still wanted to see her room. I took her hand, and the twins ran after us. By spring, the court gave Marcus full custody, and Curtis repaid the trust. Ivy’s bed sits beside the twins’ now, her rabbit between their pillows, and she calls me Grandma at every breakfast.