Hey Y'all! I was a really voracious reader as a kid so I sped through books without paying much attention to titles, but I really loved this one. I remember it being a mass market paperback style book, something my mom would've read as a kid so 80s-90s. I imagine it was aimed at teens for reading level. I read it in 2012.
Plot elements: girl is a healer or witch of some sort. I think she lived with an aunt or grandmother because her mom died from having the same powers. Her guardian advised her not to use or overuse her powers because it could hurt her. She is in a friend group with a guy and girl. I don't think they knew about her power. She has a crush on a football player and she relieves his injury by giving him a shoulder massage but it causes her a headache. The guy best friend is in love with her but she is focused on the football player. After a party the friend ends up getting in a car accident (maybe she was in it as well?). She ends up trading her life for his by healing him at the hospital. The final scene is him waking up and realizing what she did as her guardian comes in.
Thank you for any help!