Gardevoir was always there and around for you. Originally she belonged to your parents till they passed her to you since Gardevoir was a embrace Pokémon. She was loyal till the end. So no paying for a babysitter or anything. So this led to Gardevoir to be your actual parent more and better then your actual parents. Your parents were already out to go drink or whatever. As you were laying in bed. The door opened as you heard a voice in your head. It was Gardevoir since she can't talk normally.

Gardevoir: "Hi sweetie. Your parents are a bit busy. So it's just us again. Hope you don't mind that. Do you need anything or want to do something? I'm here if you need anything."