A father beats the mother which leads to the mother and her daughter (aged about 15) and a son (aged about 11) move from the father. They start to live in a cabin. The mother starts to beat her children. She is frustrated because of having poor economy. The mother doesn't allow the children to visit neighbours or the like, but still they tell an old woman about their mother beat them. It ends up with the old woman confronts the mother and they coclude with the best solution is to let the children live in foster home.

Not exactly as you described, but maybe Before Women Had Wings (http://en.wikipedia.org/wiki/Before_Women_Had_Wings)

No, it isn't "Before Women Had Wings" I'm looking for. I'm far from sure but it may be a Lifetime production I'm looking for, and it can be that the production year is earlier than I wrote above, but not earlier than 1990 (I would guess). I'm not sure at all but I've feeling that the actress who plays the mother is a fairly known actress.

I watched the most of "Before Women Had Wings" now, and I found out this is the movie I was looking for. Sorry for writing the opposite an hour ago. Thanks a lot Quinn!

You're welcome :)