How do foals grow in imagine champion rider

Foals that you bred - Go up to them in the paddock and click care (ENTER) If you brush or wash them 6times they will grow up or brush them 3 times and wash them 3 times ( you can only have 3 grown up horses (the ones you bred) at a time)
Foals that you don't breed- Don't know if you find out let me know ?? :)