Sometimes that's just the way it has to be. Sure, there were probably other options, but he didn't let them enter his mind. It was done and that was that. It was just the way it had to be.
Don't forget that gifts often come with costs that go beyond their purchase price. When you purchase a child the latest smartphone, you're also committing to a monthly phone bill. When you purchase the latest gaming system, you're likely not going to be satisfied with the games that come with it for long and want to purchase new titles to play. When you buy gifts it's important to remember that some come with additional costs down the road that can be much more expensive than the initial gift itself.
She asked the question even though she didn't really want to hear the answer. It was a no-win situation since she already knew. If he told the truth, she'd get confirmation of her worst fears. If he lied, she'd know that he wasn't who she thought he was which would be almost as bad. Yet she asked the question anyway and waited for his answer.