Need some advice please

HI there! I am new RN working in this hospital. I had a patient that just got out of surgery whose in frequent vital signs. I took all the vitals and charted it. The nurse after me gave her report and when I got home my boss called me and asked me how do I count respiratory rate. I said a full minute. Why? Is there a problem?. I'm confused. She told me that the pm nurse told her that she think I didn't count the RR because why 18?. PM nurse said she counted it and it was 10 and she thinks it was never been 18 for that pt. NOw, to make the story short she keep on saying to people that I'm making up stuff and might be not counting the RR. It bothers me because I want to keep my good reputation. I dont want people to think that I am an awful one. I work hard to be in this position. I love what I'm doing yet there's people whose questioning me. What should I do if I came across again with this nurse?. ( btw, I'm the one whose replacing her because she's leaving and going to another facility). Thank you.