Question?

I know laws are different for every state, so if anyone from Texas could help me out with this:

My daughter, who lives with her mother, has been telling things that her mother and her mother's friend put into her head. Such as, "my daddy shouldn't have cheated on my mom." This statement is absolutely NOT true, but even if it were, is it right to be telling this to a 7 year old? The friend is always telling her that I do not love her and that my dauther with my current wife is not her half sister. My ex wife also uninvited my wife and our daughter to my daughter's birthday party because her friend wouldn't be able to contain herself around my wife. What kind of an adult wants to start a fight at a child's birthday party? Also my ex wife has 3 children, her boyfriend, and the before mentioned friend all living in one small house. Not to mention they smoke in the house even though my child has asthma. I do not believe she is being raised in a healthy enviroment, but not sure if I have a strong enough case against her. Is the mind poisoning and the health concerns enough to hold up?

You can let a judge know those things and the judge will warn your ex--if it continues, her custody could
be reduced or altered.