She won't get confused. Just start ringing the bell
only when you take her out to potty, and take her out the same door every time. After a week or so of doing this, teach her to paw/ or nose the bell (not sure which one you are using?) and treat every time she even touches it, then say "potty" (or whatever your keyword/phrase will be for her) and go out and praise praise praise and reward as soon as she is done pottying outside.
Patient and consistent and she will be doing it on her own in no time
