She's now writing her own note to leave next to a book in order to make someone else feel good.
"I feel it's a great act of kindness to let a total stranger know that they are special and someone believes in them," Bromley said.
"As human beings, sometimes that is all we need. Someone to believe in us. My family was deeply touched by this message and how it made my daughter feel. We talked [about] it for the rest of the day. It made us smile."