If she's talking about you behind your back, she's not a friend. If it was a concern, she should have told you upfront. Did you hear her directly or is this something that's been passed down several people?
I wouldn't take it too seriously, especially since you can do whatever you want and there's nothing wrong with having your own interests. However, if SKZ does consume most of your conversations and your own personality, I can see where your 'friend' is coming from.
I recommend that you do speak to her directly about it if you want to fix things because keeping it to yourself will only worsen the situation as you'll hold grievances. If you do realise that SKZ does consume a lot of your interactions, as a friend, you'll need to compromise and ensure that things are reciprocal where you get to discuss what you're interested in and she gets to discuss her own interests.
I honestly don't talk about them unless it comes up in conversation or personally to my stay friend. We also found out that she isn't that great of a person as she's said other things behind peoples back (calling them a slut, body shaming etc.). I will keep mind that I shouldn't talk abt them too much though T-T