I have the same situation with a relative, and I suspect its the same channel too! she loves it, watches it all the time in HER home, and when she does, and I'm there, I simply read, play on my phone or whatnot. She knows I loathe the channel, so she's fine with me not paying any attention to it in her home.
When she comes to visit me, she will turn on the tv, to that channel, if we are not sitting and watching tv. Like in the morning when I get up, and am making coffee, getting dressed etc. but when she goes to take her shower, I turn it to what I want to watch. I personally would prefer to not have the tv on at all, but she's one who has to have it on, so I just suck it up, as she is my guest.
But we both have an understanding that she likes this channel, and I don't, and can compromise.
In the OP's case, I think she was fine to refuse to have it on, and the guest was rude to keep pushing the issue.