She is referring to the person in question as her partner, additionally, states she doesn't feel this way when playing with other partners. Therefore, I'm taking this as she is playing doubles, and her "doubles partner" is checking where the serve lands when Cindy is returning, which coincidentally, a good partner should be doing. She clearly states in the OP she (Cindy) is returning serve, and her partner was calling some serves long.
Anyway, I strongly feel, based on her continuous posts/threads>>> she has no clue what she is doing out there, and has no business Captaining a team.
I missed the "black/gray/white" post you are referring to. Where is it?
You are right I think. She is the receiver in this case. But her logic was so backwards that I seemed to have adjusted for it by making her the non-receiver in my head.