I had this scenario too and I say worry about yourself and your well being first. Run from the controlling mom as fast as possible. Its better earlier than later, especially if you were able to sense that. ALWAYS listen to your guts. The family can find another place. You can be honest and say that you had met with another family at a similar time and although you really liked them, this controlling one, that unfortunately the other one felt like a better fit so you will be unable to provide them with a spot. And that's it. You probably won't ever hear from them again. And your life will be so much better for it!!! And now YOU are in control. And YOU are the one picking the clients that get to be a part of your life. YEY!!! Don't feel guilty. Its your life. Make it as good as possible for yourself. Its already a hard enough job as it is. no need to make it worst with a picky, controlling mom that could make you miserable. Best of luck! (Don't go with the picky one!!!)