Don't worry about them thinking you're male - this forum is extremely male dominated and they always think all cyclists/tourers are male. (I get cut down on a regular basis simply because I, like you, am not.)
You don't mention where this tour is going to take place! I'm interested to know because this effects several things about your post. In regards to not being used to the weight, I do hope you're going to start training yesterday for it. This is rather important for your body so that it doesn't get the sudden shock of the exercise and the impact on the body. If over the next several weeks you bike nearly every day, starting with no weight and adding a little weight every some days, this will help a lot. You'll also be used to the weight by the time the tour begins as well as building up your confidence for encountering various riding conditions/situations. As for high/low weight, weight is supposed to be low and of course you know that heavy things go at the bottom of the panniers, evenly distributed, preferably towards the back. You stated that you told us what all you're bringing, but I don't see such a list. If you gave us that list, it would help as we could tell you what to leave behind. Personally, most of my tours have been 18 pounds for the rear panniers, plus 3 pound tent, 4 pound sleeping bag, tarp and closed-cell roll pad. Plus a large handlebar bag. So definitely under 35 pounds. Welcome to the wonderful world of bike touring!