H.J.
Tracey- I hate to say it but, it isn't you position and getting into the middle of a relationship will only cause grief for you. My suggestion is to do your job and let her do her "tax" stuff. If she messes up it will be between her boss and her and you'll come out the hero. I own a business and have 38 staff members ...trust me the boss knows what's going on but, can't always say or ask for help.
Good luck! H.