I did something similar once...just with a less happy ending. This girl had a dream to be a guest on Oprah, and had an idea for a mobile app that just might get her there. I was in love with her and thought that it would be a very thoughtful Christmas present to make the app for her. She was a designer, so she just had to style it and launch.
I built the app over a few weeks by sleeping an hour less each night, ultimately giving it to her for Christmas. She loved it. Unfortunately, things went way off course between the two of us. I don't think the grand gesture helped. It's a lot of pressure to put on a person.
If I had to do it over again, I probably would, but I sure as hell wouldn't have let her go at the end.
We don't talk anymore and she has let the project go. C'est la vie.