Her uncle just contacted us trying to get into her life since he is " family", I d
o not know this man, and do not know if he is truely not in contact with his brother, my daughter's dad. I do not want her to know him, them, so do I have the right to push them away?
Your post does not mention why the father's rights were terminated or why you do not want the uncle involved. Perhaps it is because you do not want the father's nose back under the tent.
The grandparent's MAY be able to get visitation rights under the family code, but it is unlikely an uncle would be able to do so.
You do not mention how old your daughter is. Be careful in how you deal with this situation. She may later resent it if you block all of the dad's family. And, in these days of social media, etc., it is quite possible the uncle or other family members may be able to make contact even without your assistance.
I am not suggesting that you MUST allow access. I just recommend consulting with a local attorney and consider your options carefully.
In certain circumstances, grandparents may have rights independent of those of the terminated parent. I'm not a family law practitioner, so I couldn't say for sure (perhaps a family attorney on here could clarify). But, if you continue to have questions about the former father's family's ability to insert themselves into your daughter's life, you might consult with a family attorney in your area for advice on your particular situation.
Nothing in this answer is intended to be construed as legal advice. In order to obtain legal advice on any topic, you will need to consult with an attorney on a private, in-person basis to discuss the specific facts and circumstances surrounding your issue. Neither this answer nor its particular contents are intend to create an attorney-client relationship between you and William B. Short, Jr. or between you and Coats | Rose, PC.