Sorry Kelly, don't know of anyone that makes a female
looking Mjolnir armor. But you still have a few options.
There are some people here that make mjolnir armor, and in reality, the female spartans wore the same armor as the males. If you are not too busty, you could probably fit onto one. Most can be made with elastic or velcro straps so that it could fit you.
If you're up for making your own, go for it. We've got tons of reference pics and skill here to help you out.
Also, if you're not set on female Mjolnir armor, have you considered
female stormtrooper armor? You could search the web for some help on those, I even see one for sale on eBay every once and a while.
Good luck and welcome to the site.