J.O.
The Tubes at Irving Bible Church (FREE)
http://www.irvingbible.org/index.php?id=1516#c5969
Frontiers of Flight Museum (Adults: $8, under 3: FREE)
http://www.flightmuseum.com/index.htm
They have a Jay Jay play area but not sure it's worth the price for such little one.s
Interurban Railway Museum (FREE but accepts donations)
Story time is on Fridays at 10:30
http://www.plano.gov/Departments/ParksAndRecreation/Recen...
Owens Farm (this one is outdoors and it's closed until March but so much fun to feed the animals!)
http://www.bobevans.com/ourfarms/springcreekfarm/admissio...
Fritz Petting Farm (this one is outdoors and only open June and July) FREE
http://www.cityofirving.org/parks-and-recreation/faciliti...
Interskate (Mom and Tot on Wednesday mornings) $3 admission
http://www.interskate.info/home.cfm?page=3
I've also heard good things about Paradise Pond and Thunderbird Stroller Skate but have been to neither personally.
http://www.fbcgrapevine.com/groups/children/paradise-pond/
http://www.thunderbirdskatecenter.com/strollerskate.php
Have fun!!