Not Really when she came, Sean Paul was already peaking. Plus there were Nina Sky, Janet Jackson (with Elephant Man or Beenie Man), I'm not counting Beyonce cause she hopped on the dancehall bandwagon with Baby Boy (One of my favourite song tho, and also Beyonce is my fave).
And if you study each one of her eras there was still someone before her who peaked... She just has the appeal of the public and the commercial success. But she's never really the trendsetter, just the one you remember.