You don't really mention the ages of "family" - whether it includes toddlers, school age kids, or teens. That would make a difference, but here are a few ideas:
Summerfest at Gaylord Texan is fun, and if you don't buy anything there, your only cost is parking: http://familyeguide.com/SummerFest-Gaylord-Texan.html
Bass Pro is kind of fun to walk around. They have weekly fish feeding and fishing, plus periodic activities for kids:
http://familyeguide.com/Indoor-Play-Areas.html
http://familyeguide.com/Family-Events-at-Bass-Pro-Grapevi...
Take advantage of the early and late hours to get outside for a walk to the park, visit to the duck pond, etc.
In terms of eating out, here are some local family deals (kids eat free, etc.): http://familyeguide.com/Kids-Eat-Free-Deals.html
Visit the Family eGuide Calendar for more date-specific events as well: http://familyeguide.com/user_vcalendar/week.php?id=3&sid=
Good luck!