EeRynn don't want to go to school

This morning EeRynn woke up and said she want to go to her grandmother's house.

Mommy : Why EeRynn?
EeRynn : Because I want to play and I don't like school
Mommy : Why don't you like school?
EeRynn : Because I don't like practice for concert. It's very tired.
Mommy : Emm, why not mommy watch your practice today? Let mommy ask Ms Fidza whether I can be there today, OK?
EeRynn : OK

I am thinking, this is her first time going through a form of discipline, consistent practice to achieve something. How do I encourage her the concept of perserverance? If you have good idea that work for you before, please send me a note.

Thanks!