You don't need to worry about it. I'm in a regular Facebook group for my cruise, and after reading this thread I went to this woman's FB page to see for myself. When you request to join, one of the questions it asks is if you understand that the way to find your cruise's FB page is to use a given link. So I pasted that link into my address bar & went there, and looked at the listed cruises.
My cruise page & its administrators were listed. I also noticed that the basic FE info sheet that my cruise uses was reprinted with permission from that woman. Maybe it's been edited, but there are no strict rules on it: no minimum spending amounts, no "don't buy this or that", no "you have to identify yourself as the giver". Nothing strict or weird. I also recognize that this is the same info sheet that the FB group for my last cruise used.
I've been a member of my cruise group for months and it's nice and normal. No controlling behavior in any way, just folks prepping for their own cruise. I'm a member of my cruise page's FE exchange group, too, which is also nice & completely normal with no strict rules at all. I checked my group's admin & member list & didn't see the woman who runs that other page on either list.
So just because your cruise page is listed on that woman's website, doesn't mean it's controlled by her or will be an unpleasant experience. Honestly, as someone who has completed two recent FE exchanges via Facebook and is in the process of preparing for a third, and has never had the slightest hint of a bad experience, I think some of the posts in this thread are exaggerating the scope of the problem. If you just avoid this one woman's particular page, you'll very likely have no problem at all.