On https://www.starwars.com/news/star-wars-the-high-republic-show-204-reveals this is mentioned about Yaddle:

> The Force-user is the same species as Yoda and Grogu, and she'll play an important role by the end of Phase II.

As a sidenote, I found this page by simply Googling "Grogu species site:starwars.com"