I don't think its rude. I think its strange that they would do that, I personally would have stayed at a sister resort, but I have been a DW bride, so I would like about the bide and what might bother her, people who don't know what its like would not think about that.
I don't think she went there to control your wedding, she got a good deal and decided to jump on it and I understand that. If when you get there she starts acting sort of bossy, tell her that you are excited to figure these things out on your own and really don't want her opinion, but in a nice way of course. If she has a bad attitude and starts to say bad things, they cut her off right away. If she truly has good things to say that might help you, then I think you should hear her out.
I think you are doing the right thing by just letting it go, there is nothing you can do about it, so why stress about it.