Why Melanie's mom hate Jake n was ok later in Sweet Home Alabama

I am watching this movie on ROMEDY NOW now after a long while. It is one of my fav movies and I always get stuck at how mel's mom quickly changes sides at the climax. 

The whole movie she is seen calling Jake 'a quicksand' angry over mel bonding with Jake at the pigeon creek party. She clearly expresses how their and mel's life would change with mel marrying Andrew and even persuades confused mel to not back out before going to alter. 

Few min later, she was happy when mel breaks up with andrew and runs to find Jake, and she is seen joining celebrations and later in post-credits too while she is happily posing for family pics with mel-jake and their daughter.

Can someone explain or m i only confused? How come this sudden change in heart?