I found this template for the invitations here
A slumber spa birthday partyApril 3, 2010
Our little princess Isabella is turning 8 at the end of this month. The 8th birthday is a rite of passage for our kiddos because it's the first year they are allowed to have a sleepover. Isabella loves all things girly, especially pampering and spa treatments, so she decided to have a slumber spa party. We spent this afternoon making invitations for her friends and hand delivering them for the big day!