When LCD shopping, an important specification to look at is "response time". It is expressed in milliseconds; the lower the better. A slow response time will show the trail you observe on Mom's TV. And it is more visible on a video which contains lots of movement. A TV with fast response time can handle rapid movement without trailing. AFAIK there is no adjustment you can do; response time is an inherent specification of the LCD panel inside the LCD TV set. If the same model is still available, you could try finding one on display and see how it looks. If it's better than Mom's, there may be some defect; worth trying to negotiate a replacement. Response time is one of those things LCD engineers are constantly working to improve, eeking out incremental improvements bit by bit over the years.

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