I have been into Welcome Home (the ARG) recently, and I made my own OC as a result. You can read the first part of my character's description in the profile (which I based it off of the website's ones). However, since I had to cut off, here's the full description right here, starting from the brown letters:

Some found drafts reveal that Desiree was a one off character intended for an hour long special episode. Premise of said special was that she visited the neighborhood for vacation due to her overwhelming anxiety. Initially, she would be shown as a gloomy and cautious character until Wally and cast help her become a more confident self.

Unfortunately, this special episode was scrapped because the producers felt concerned the plot would be too serious and depressing for kids. A Desiree puppet was completed however before this decision was made, however. Rumors has it that it is stored somewhere in production storage although it has yet to been found.

It is implied that if the special had not been cancelled, then Desiree would've joined the cast and had an especially close relationship with Wally. Episodes centered around her would have been about more serious themes such as: coping with anxiety, growing up in a divorced family, and the after affects of bullying.