updated 06/23/2010 AT 11:00 AM ET
•originally published 06/23/2010 AT 8:00 AM ET
For Kellie Pickler, June 15 has long been “sad and hard for me,” as it is the birthday of her late grandmother, Faye Pickler.
But the traditional sadness of the day turned to happiness last week, when Pickler’s boyfriend, songwriter Kyle Jacobs, proposed on a Florida beach at sunset.
“It turned out to be the most amazing day of my life,” the fifth-season American Idol star, 23, tells PEOPLE. “My whole world changed. We both feel like we got my grandmother’s blessing.”
Pickler considers Jacobs’s proposal a moment she hardly could have imagined. “I remember saying to Kyle, ‘Baby it’s like I’m dreaming – but if this isn’t real, I’m going to be very upset!’ ”