I lied to a kid and told her that her dad was in a relationship
Is it something you wanted to say on purpose?
No but she was being a brat.
You should not lie to children because you don't like them. If you encourage lying around kids they will lie more and can create problems for them growing up.
She asked me and so I just gave her an answer.
It's OK to give an answer when you are asked a question, but it's wrong to lie, especially to children.