If you missed the first WoM podcast, you should go back and do that. S2E21.  But if you don't feel like doing that, here's the original introduction:

Ada has Phelan-McDermid Syndrome: very rare genetic disorder caused by deletion/mutation of shank 3 gene.  Only 1700 known cases but believed to be highly under diagnosed.

Ada is our angel baby magical  fairy mermaid who marches to the beat of her own drum and teaches many wise lessons along the way.