I watched this around 1998-2000. I remember very little and I am not sure if I'm confusing and mixing two items into one.
I am also not sure if it was a movie or a television series. It was very long, so might be a movie, but it ended with 'to be continued' so it might well be a TV series. It was filmed in the US.
It was about a family, the parents were witches and they were killed by witch hunters. They had two children. Older son about 18, and a young daughter about 5. After their death, the kids were taken in by their grandparents.
At some point, the guy got into a fight and was stabbed (I think) to death. The grandparents took the little girl and ran away to another location to keep her safe. During their drive, they witness a car crash on the road. When they stop to help the survivors, other witches came out of nowhere, abduct the girl and disappear, apparently the car accident was a scam to get the girl.