Puppy Dog Pals Doghouse Playset Stabilizer

My daughter got the Puppy Dog Pals Doghouse Playset as a gift. It was great, except it was designed poorly so it tips backwards constantly. She could only play with it propped against the wall. This support lets it stand on its own. 
 

To get the fit right, I traced the outline of the bottom with a touchscreen and a stylus using Inkscape. I then extruded it in openscad and printed a single layer to check the fit. That process seemed to work well. 
 

I attached the final print using m2 screws through the base (see pics) and a dab of glue on the support that connects to the slide.