I'll try to be helpful, and other people will try too - but the reality is that nobody can offer any useful advice at this stage because nobody knows what you're trying to achieve.
But, I'll take a guess at it....
Woodland scene, white floaty dress - I'm guessing that you're going for an innocent, virginal look, and if so then that's a starting point, although nobody ever knows exactly how something should be lit until they actually do it, and the more experienced the photographer is, the more true that statement is.
Let's look at your equipment - it's totally inadequate if you want to control (rather than just add to) the light. If you want to control it, you probably need 1200Ws of lighting, not 300. You certainly won't be using your softboxes because if you do so, there will be virtually no light reaching your subject. Testing for yourself though is the only way of finding out whether I'm right or totally right on this
So, maybe your best bet is to use your flashguns behind the model, to backlight both her hair and her dress. That may work if it's dark enough. I wouldn't use your flashguns for anything else.
This leaves you with just ambient light on her face, you can't actually light it so why not do what Profoto do, and create the "lighting" in Photoshop and pretend that it's a real location photo? Dig at dishonest advertising aside, this is actually the best, and probably the only way of doing it given your resources.