Update:
Her flight was further delayed till 8 PM. They started boarding, the pilot stopped the boarding for 30 minutes, then let everyone board. He closes up the plane and then tells everyone there are brake issues. They sit in a sweltering plane for 1:45, my daughter holding her 18 month old, with one bottle of water. All complaints for AC and drinks were not responded to. Finally, at 10 AM, the offboard and are told to wait in line for a transfer. After an hour in line, they are told there will be no transfers and they should have a plane shortly. At 11 PM, they are told the new plane is on the other pier and to get there in 15 minutes, as it won't wait for them. So my daughter runs from B to C pier at BWI, and that plane departs at midnight (so there was no reason to run). She lands at 2:45 EST, than has an hour drive home. Thunderstorms aren't Southwests issue, but plane issues and rude treatment are. Her mom works with the Attorney Generals office in Maryland, so I've unleashed that hell hound. Scorched earth to follow.