I posted here before and got some help but if it's not suitable for here maybe a mod could move it.
Short version of the story.
2 women and 1 man siblings with the same mother and father and the parents are both dead.
Woman comes along and claims to be half sister with the same father as the other 3.
What tests and with who can help prove or disprove the relationship.
Blood tests or DNA tests and how do you find a reputable company to carry out the tests
Any ideas appreciated