If you are looking for a fun family activity, do checkout the Grapevine Vintage train. It makes a round trip from the city of Grapevine to Forth Worth Stockyards and back.
This train offers both air conditioned seating as well as naturally air conditioned seating. I preferred the natural environment. The fresh air is always better and you enjoy the ride more that way. It is a very relaxing ride and kids will enjoy seeing a bunch of turtles on the way as well. They get to feed them too.
You can also look forward to bunch of cowboys doing a show for you during the train ride.
I thought the cowboy show was pretty cool. I also enjoyed window shopping at Fort Worth Stockyards.