I’m another one who chose a school that was not as selective as my parents thought I might attend. And although there was puzzlement at my choice, my parents came to see how I thrived in college and how it was a fabulous experience for me and ended up being very glad I chose it.
I do think it’s fair for you to ask your daughter for her reasons for selecting Auburn, not in an accusatory or leading manner, but out of curiosity and seeking to understand. If there are reasons that you have concerns about (a significant other attending, or the lowest cost, or whatever) then I would let her know that you will support her whatever decision she makes, but that you have the money saved up and are happy to spend more, or whatever the various issues are that raise your concern.
At no point, however, would I make negative remarks about the quality of the experience at Auburn. It’s a fine institution beloved by many. But if she doesn’t have housing locked up, perhaps bring that up as an issue. But make sure you are supportive of HER and her decisions. You can make sure she’s thought about various issues, but do not leave her in any doubt that you want what is going to make her happiest and most successful as a person (see @CMA22’s post for what I mean by successful). And once she is firmly decided, don’t mention the other school options again.