First laugh

I was having a fever yesterday.
This morning I decided to lie on the bed longer.
Both my children were already up and I let them play on the bed for a while.
Qash was crying because she felt bored lying on the bed.
So, I picked her up and let her lie on my tummy - on her belly.
She looked at her brother who was playing with his toy car, on my right.
She laughed at her brother.
I don't know what triggered her 'funny' sense.
Haha..
And her brother continued playing with his toy car.