Kids Muze could be a great thing for you! if you are staying in the area longer, you might consider joining. with the heat of summer setting in...
On 2499, there is WinKids. expensive for classes, but on mondays they have open gym. although it is $10, it is pretty awesome if you want your toddler to get a good workout. they take great naps afterwards!
waterplay-the waterpark by the city of lewisville in EAST lewisivlle is awesome. it is smaller than the one by the high school, less crowded. Superior for tots under age 3.
The kroger at 3040 and Morriss / Gerault has a splash pad / water fountain out front. a fave of local moms. grab starbucks and walk over to play. after about 4:00, it is mostly shaded too. Central Park in lewisville is great for that age. the 6 month old can swing while the older tot plays very nearby.
the roller skating rink in lewisville has a wednesday program for strollers and tots. i haven't been, but it sounds neat!
have fun.