According to the fan who posted this up on YanSe, she said that it was the first time that they have seen Yeon write so many chinese characters for the first time. I think Yeon had wrote this beforehand and then gave it to the fans. It's really sweet of her <3 Her writing isn't bad either!
Translation: "Thank you for all your care in the past few days. I won't forget. Don't need to send me off. See you another day."
Source Credit: YanSe (leechaeyeon.com)
Translation Credit: ST@Yeonic