The only advantage she has over Thor is speed and fighting skills... wait, someone will tell me that Thor has just as good of fighting skills...
Anyway, Thor also has a little more than 10 years as well. But I'll play along with her being as good as Thor with it (as that's what it seems you want).
She's basically Thor with a lot more speed, a lasso, and bracelets. Is that enough to beat Prime? No, no it's not. Especially since he's pretty darn resistant to magic.
Mjolnir really doesn't add much to WW's chances of beating Prime, tbh. It does give her more defensive capabilities to survive a bit longer, though. Her only real shot is to lasso Prime and hope its haxxed powers somehow make him break down and cry or something. Even then, it's unlikely.