Karma actually means "action". Basically, from your actions you sow the seeds for your future. In addition, your ancestors to some degree sowed the seeds that shaped you at birth, ie, you were "dealt a hand of cards." It's up to you to play that hand well.
I reject the "tabula rasa" or "blank slate" theory in psychology. To me, any person comes complete with all kinds of drives, reflexes, etc.. Based upon the tendencies of your rancestors, you have a high probablility of being a good/bad person.
That is, I don't completely believe in "freedom of will.' I think it's a highly overrated doctrine pushed on people (and the organizations that do that pushing have done plenty of lousy things themselves).
Any good you do will come back to you and any bad will also.
Personally, I don't believe in reincarnation or the immortality of the soul(s). I believe that everything is taken into consideration.
So it's important to raise children especially with a moral tradition that molds their character and gives them hope for the future. And if you can't do that, I suggest you not have children.
I think the trick to raising children is to understand what they are all about. If they have too much unsupervised time on their hands, they could get into trouble. And bad habits and drives from early on, are difficult to stop as life goes on.

I don't see the point of karma without reincarnation? How can good or bad come back to you unless you are able to continue it sometime? What if a person isnt' able to reap their good/bad in this lifetime? Would all that be invalid?