I'm not gonna lie it looks like a lot of assumptions have been made by some of the posters in this thread, that or they've watched too much CSI
I'm not sure of your location OP so I will base my answers on the UK Fandom specifically as I have worked security at their events for over a decade now.
Furries, at their core are no different to sci-fi nerds/trekkies/any other Fandom with the exception being a lot of furry content is self-created rather than being of a specific set of characters from a show.
Now is there a section of the Fandom that is into the adult things? Yes. As there is in any Fandom.
Are there people who take it too far? Of course.
But a lovelier, more friendly and accepting bunch of people I have never met.
If you are truly worried it may be worth sitting down with them and rather than making assumptions, ask them what /they/ find interesting about them, is it just the cute costumes or something else?
In the UK the age of attendance at most meet-ups is 16-18 so maybe in a few years if she's still interested and it's not just a phase, take her along to a local meet.
If you have any further questions feel free to ask