This is a YA book from the 70’s or 80’s (I think). It is about two teenagers (Robin-male lead and Jenny-female lead) who fall in love and discover that years ago Robin’s mother killed Jenny’s sister in a drunk driving accident. Robin has blonde curly hair and he describes Jenny as a Modigliani girl.
“When We First Met” by Norma Fox Mazer
Thank you SO MUCH! That is it!