Lacie
Lacie is Vanessa's friend who was first mentioned when Vanessa was on the phone with her ("Hail Doofania!").
She appears in "Dude, We're Getting the Band Back Together", "Brain Drain" and in the "Mix and Mingle Machine" ("Cheer Up Candace"). She was first addressed by name as Lacie at Vanessa's costume party ("Druselsteinoween").
In "Dude, We're Getting the Band Back Together", we learn that Lacie has been friends with Vanessa for at least six years when, while showing Perry his preparations for Vanessa's 16th birthday party, Doofenshmirtz produces a picture of Vanessa's 10th birthday wherein Lacie is seen.
Along with the rest of Vanessa's group of friends, Lacie is allergic to bees as shown in the episode "Skiddley Whiffers".
She attended Vanessa's party in "Night of the Living Pharmacists" and is seen in Vanessa's class in "Doof 101"