I have done a little bit of brazing, gas, and arc welding. But, I am just a hack. I want it to look professional, so this is not something I would tackle without substantial experience.
My backup solution is to build a primo gate from clear redwood. There's one around the corner that she likes -- it has a little heart cut out in the middle. That should win a lot of points with the little gal.
Thanks again for the suggestions.