E.W.
I'm not sure what your friend defines as too far of a drive, but I highly recommend the pumpkin patch in Argyle. I also live in Keller, and it's about a half hour drive. You can visit their website at www.pumpkinexpress.com for more info. The train ride is fun, and there are a couple of bounce houses, a hay bale maze, lots of photo ops, and, of course, pumpkins!!
I have also been to the Flower Mound pumpkin patch, which I USED to really like before I discovered Argyle. Flower Mound also has lots of activities (but no train, although they do have a hay ride), but the layout is difficult to maneuver through, and it also seems to be more crowded. The other trade-off is the cost. With Argyle, you pay for the train ride ($5 per person unless age 2 and under), whereas with Flower Mound I think all the activities are free. BUT, if you're actually looking to pick out a pumpkin, the ones at Argyle are at least half the price of Flower Mound. That's been my experience anyway!