So my mother-in-law redeemed herself. She took Meg to the airport. After talking with Meg a little bit more I found out the real story behind what happened, which I figured was the case. Meg's aunt was telling her mom that she should just have Meg take a cab so she could sleep in since it was so inconvenient (read: she would also have to get up to let her mom back in the house). I would expect this from her aunt so it wasn't a big surprise...after all, her aunt and uncle always make it clear what is inconvenient for them, did I mention our wedding day was inconvenient for them? They even tried to get us to change that date because they would have to make a trip down to Ohio from their summer home in Michigan. So sorry to inconvenience you all.
Okay enough complaining about my in-laws