I have no idea if you are or if you aren't. Normally, we expect a mother's love to be unconditional, so for them to claim to hate their child, we think either depression on the mother's part or the child has done some really really evil things.
So if your son tortures small animals - yanbu
if he leaves the top off the toothpaste - yabu
if he murders old ladies - yanbu
if he forgot to turn his bedroom light off - yabu
Generally, in order to help others to understand, people explain why they feel the way they feel. Without that, it's simply impossible to even begin to know whether yabu or not.