I'm going to tell my mom she can't babysit my child anymore
What is your mom doing wrong while babysitting?
She is always letting my kid watch TV, eat sweets and play too much.
Babysitting other's children can be subjective. I am sure if you have a heart to heart talk with your mom, she would be accommodating and change her behaviors with your child.
I'm going to tell her that she's lazy and doesn't do her best or help me raise my kid right. I bet she will leave then.
It sounds like you need your mom to help raise your kids but it isn't correct for you to criticize your mom when she makes mistakes with it. Help your mom to do a better job rather than tearing her down.