Confused!

[Merry]

OH was looking at his DNA matches and saw a tree with his grandmother on it. He sent a message to the tree owner and they replied saying his grandmother is their 1st cousin 3x removed (but didn't say anything more!).

OH is out, so he texted me to ask if I could look at it. Trouble is, I can't find anything about this tree owner. I can't find her on his DNA match list and if I search his grandmother's name she only appears on one tree which belongs to someone else.

Why can't I find this woman and her tree??