If I were you I would not take her to a resort for you 5th anniversary.
If she is super close to taking the plunge make it personal, chose a destination that will make the anniversary memorable and where there will be one BBC ready to take good care of her. I believe you know her well so you will be able to find a guy the fits her criteria. You guys can meet with him for drinks and more if there is chemistry then you can have a proper anniversary celebration with him. Choose a guy who has some experience because he has already been with first time couples. This way you get the unforgettable memories.
Going to a resort is a great idea four your anniversary once she has taken the plunge not before because she may feel pressure from the environment.
Just my 2 cents