Thank you. I can't see the bit where it says that the forth person played any part in separating her (Yvonne) from the McCanns.
That depends on who is doing the counting. "Meanwhile a fourth individual came towards the group and identified himself as a journalist. The witness alerted the couple to the type of statements they should give and that it would be better for them to keep silent.
At this moment, the third person, who was always near to the couple and the witness, moved the couple away from her and the three of them talked in whispers for some time.
After this, and leaving the couple behind him, he approached the witness and told her that the couple did not want to speak any more with her, nor with anyone else.
The witness replied to him that if the McCann couple felt the need to talk to her later, she would be at their total disposal."
That is counting from YM POV where she is not counting herself.