Guessing MIT OCW may be a better online option than, say, Khan for a summer intro to calc (calc 1/calc AB)? I bought Stewart and also Schaum's Outine just to have around for reference, but she'll need something more substantial. I am looking at this course https://ocw.mit.edu/...-2010/syllabus/ I'm wondering whether this covers calc 1 or calc 1+2 ? Maybe I can look at a syllabus for AB and figure this out...
That OCW class covers the Calc BC material. (MIT does calc 1 + calc 2 as a one semester course)
Units 1, 2, and 3 cover the Calc AB material, along with L'Hopital's Rule from Unit 5.
Take a look at this OCW course also: Highlights of Calculus by Gilbert Strang. It's not a whole course, but instead is a nice introductory overview. I think it would be great as a summer preview, especially if your student is a big picture learner. Professor Strang is a fabulous lecturer.