Ah moms. Mother in laws too, siblings, cousins, aunts, uncles, grandparents. We love 'em, but they can drive us up the wall!
Others have suggested you get a reading with an AIRR member and I agree with that--check us out at
www.readersandrootworkers.org
The first thing to accept is that she is your mom--at the end of the day you love her and you want to be "right" with her.
Now, with that said, it is not ok for her to undermine your authority with your child, speak badly about your partner, and make you feel like you have no control. I am also a big fan of peaceful home work and if you have not tried that angle I would.
Make a honey jar, put her in it and put yourself in it--maybe your child and partner as well. Petition that she will be open to your ideas and cooperative, and also pray that you can have an open, loving heart towards her. If that does not start getting you the movement that you want you may have to do some work that has a bit more of an edge.
Get a reading to accurately assess the situation.
good luck,
Bri