Top colleges have "ability to overcome obstacles" as a top criterion. Legally, the colleges do not need to know about any health condition, but in many schools, it is a plus, not a minus.
Accommodations through the disabilities office can make it possible for your daughter to go absolutely anywhere. This can include excused absences for medical reasons, reduced course load, notetakers for missed classes, extensions on papers, and extra time on testing if needed for medical reasons (such as a break to walk around). The disabilities office will provide her with a letter for each professor, without specifying the actual diagnosis.
She clearly has the drive and determination and should not settle for a lesser program because of her health condition. Saying that she should look at safeties due to illness is, to my mind, like saying a female or minority should focus on safeties. (That is not to say that anyone should not have a safety or two, but not for that reason.) Disabilities/medical issues are the next frontier of diversity and with proper supports, she should be able to accomplish anything she wants to accomplish.
The guidance counselor can write about her perseverance in the face of the spinal problems and surgeries. She can also write an essay about it in the common application (though personally, I recommend that the main essay be about something else, and that she do this in the supplementary, optional essay).
Question: is this an ongoing problem or has it now been dealt with and aside from recovery and residual effects, does she have a good prognosis? Or is this a chronic or intermittent issue that will continue?