Hi honestly i dont think you do my son use to do the same thing when he was 3 i think its because of the dora song lol hes 6 now and talks perfectly fine.
I think she might just like Dora. If it continues and starts with other things I would get her checked. Does she copy what you say like."what are you up to?"
and repeats it back to you? If she does then I would take her to a speech therapist
I think many children repeat things.. it mean nothing other than she enjoys Dora..I have heard many children asking questions over and over , in my opinion its what they do around this age ...
I would only be worried if that was the only thing she was saying. But as you said, she is normal and bright, so like the others said, she probably just likes Dora. Heck, I like Dora..lol.