Thanks for being so kind and understanding to your daughter and trying to give her this opportunity.
I would personally recommend looking into programs in your community. If a university is near by, they may very well have a strong program and something available yearly for elementary school students.
The lego set is a great idea to try, but I know when I was 6 or 7 my parents just gave me stuff to tinker with. E.g., I had toys break, and instead of just throwing them away, my parents would pick the ones they deemed safe and let me take them apart. It was a load of fun. You may want to consider taking her to the store and showing her that set, or maybe ask a highschool teacher to recommend something they'd do. By showing her the set she might make it a goal to get the set, and there's always Christmas and birthdays in the future if she shows interest that you can invest in it!
Good luck, and welcome to Chief Delphi...
- Genia Gabrielov