First, it would be intereting what you call different visitors... is it just the number of viewers, or where they come from or what? I'll assume that it is the number
I removed the link since it was completely unnecessary... your question is if weebly and Google Analytics can display different visitors or infomration... and the answer is yes. No software is going to match whatever any other software says for many reasons, two of them being that each of these softwares may define "unique visitor" in a different way and, most importantly, the algorithms for both grabbing and calculating the stats will be different.
These difference can be huge but if your site is doing well, the tendencies should be similar (meaning that if you site goes up, goes up... how much, it will be a different thing for each of them)
In summary: the answer is yes.