So my sister has two kids with a man but they are having problems right now I was wondering what her rights we're to the two boys? What if the two boys don't have his last name but his mothers last name what can she do about that? Is there anyway it can get changed? And if he had a preveast charge against him of child endangerment does that stay on his record done even if his anger management classes and his and community service hours are done with?

She has all her rights, and have the right to file for custody of the children, and to fight him in court if he files for custody. They may settle for joint custody, or he may end up with visits.

If the court feels he is still a threat they may order vists to be supervised.

** if he record is still on all depends on the order and plea agreement from the court, so it may or it may not.
But if she has proof of these changes, she can use them in court as evidence anyway