Here's one of those secrets that many parents of gifted students don't know: Often gifted children are not gifted students! In other words, they do not necessarily do well in school. Why? Because they often need to be taught differently and are not. In a number of states, GATE programs are inside Special Education departments. This is because students at both ends of the spectrum need to be taught differently.
While I cannot guess about the Stanford program, the others might be open to someone with high test scores, but not great grades.
In the state of Michigan, there are two online high schools. They are:
Michigan Virtual High School and
Central Michigan Online SchoolYou should take a look at both of those as well. Of the two, only Michigan Virtual High School offers a diploma. It is free if you can get your local school district to pay for it. If not, there is a cost involved.
I would talk with all the schools that have been mentioned and work from there. Laureate is part of the long-established
Laurel Springs School, so you might want to start there. But, yes, definitely look at al of them.
Tom Nixon