Arlene,
I know it has been a long time since your post but if your sister ends up north of Dallas(plano, allen, mckinney, frisco), you can trade to tanglewood resorts on Lake Texoma. There isn't a whole lot to do there but swim, fish and golf, but it is only about an hour drive from the places mentioned. If she is in Dallas or Fort Worth it would be alot longer because of the Traffic. It is horrible around here sometimes. Hotels are closer but who wants to pay for that and maintenance fees, that's why we bought timeshare, right??