I like it, just depends on how its Implemented I guess.
Another thing would be to have each child born with a "pre-set" personality that prefers X, Y, and Z ... and once the child is born you can choose "I want the child to be raised in X fashion" or some such.
Then you can either have a simplistic relationship between the child's personality and the way you choose to raise him ... or you could make things more complex/subtle and less gamey.
For instance, simplistic would be that a child is born with loving combat, indifferent to magic, and abhorrent to diplomacy. Then if you choose Combat he gets a larger stat boost and increased loyalty, while if you choose diplomacy he would have a chance for stat penalties and reduced loyalty.
Having a more complicated system could be.... having Child Rearing Choises of Strict, Moderate, and Laid back ... over the choices of Martial, Magical, and Diplomatic*.
Then, the child would have hidden and preset affinities for either Martial, Magical, or Diplomatic. If you choose the right one, your child will get stat bonuses. As for Strict, Moderate, or Laid back ... if you choose correct you get stat bonus and loyalty bonus, if you choose 1-off you still get a smaller Loyalty bonus ... yet if you choose 2-off you get a loyalty penalty. And lets suppose that choosing Moderate never gains a stat boost* even if its the "correct choice" for the Child's personality.
*makes things more interesting.
** Diplomatic children could add to your ability to making deals, or make better deals for you, increase prestige in a city, and be able to be married off (or arranged marriage in general) more easily.