I have a 5yo DD and a 2.9yoDS. They absolutely love each other! They do fight but get over it quickly.
The reason I am worried is that sometimes I think my DS is more bonded with his sister then he is with me. Not that it's a competition but that maybe he isn't bonded enough with me which is partly to do with how joined at the hip they are.
He does come to me if he is hurt or if they fight.
Does anyone else have this?