Need Help with Reference

[heronurse]

So I applied a job while being employed and luckily I landed an interview and it was today. After speaking to the manager and HR they want me to do a reference check through a website survey. They are asking me for 3 reference, 1 NM or supervisor then two co workers. I'm not worried for the co-workers because I've been close to some of them but my problem is with my supervisor. How can I approach my supervisor for this? My supervisor is really really good to me and helps me alot and I'm afraid that if I ask them to be my reference that her relationship with me might change or the facility might put a target on my back. Gossip in my place is worst like Grey's anatomy lol. Another problem is that If I ask them to be my reference, and didn't get a job they might think I'm really really trying to resign and their relationship to me might change.

Any tips how to do this? Thanks!