I don't mind saying in advance that in my opinion jealousy is normal and healthy. Jealousy arises out of the fact that children love. If they have no capacity to love, then they don't show jealousy.
Donald Woods WinnicottHowever, it can't be helped; mothers, if they do their job properly, are the representatives of the hard, demanding world and it is they who gradually introduce reality which is so often the enemy of impulse. There is anger with mother and hatred is somewhere even when there is absolutely no doubt of love that is mixed with adoration.
Donald Woods Winnicott