Why, would anyone deliberately set out to hurt their child?

Some people I know have recently married. They are very young (in their teens), and both families were a little unsure about the wedding and whether it was a good idea. But, they did marry and are a very happy little couple. One parent, however, is apprently determined to be as horrible as possible to her child over the whole thing. she leaves voice messages and sends emails that are full of hate. She even went to far to say that she wished her child's spouse dead. The couple are both smart, educated, and kind. I simply cannot understand how anyone could be so cold to their own child.

As for me, this has been a rough week. Not sure if I mentioned that I am a long long way away from my husband and have been for some time as he is deployed. I have worried more than ususal this week. I don't know why. I am hoping that it is unnecessary extra worry.
I worry more when the phones are out and he can't call. This didn't bother me so much until the time when I could hear gun fire. Now my nerves are on edge much more often. I can't wait for this all to be over - for me and for all the other families out there.