The DNA results taken from Tanay "Jackson" revealed that she is not Tito Jackson's daughter and no sister of 3T. Despite of Tito Jackson denying her as his daughter, 3T took a DNA test with Tanay to proof that she is not their sister. In The Jacksons: Next Generation - The Mother of All Confrontations (S01E04) Tito tells 3T that he took a DNA test with Tanay Jackson which was negative as well. He didn't keep the results, he gave them to Tanay. But 3T still have the results of the DNA test and they also send a copy of the original to Tanay.
The results are read and shown by Taj Jackson: