(I'll touch this post ...) For any first-timer, you're not alone ... male or female. And might I say that you are not, "... two women in a man's territory.", but you're two women in a predominately man's territory. I am not at all making light of your situation. I just want you to know that women have made tremendous strides in a predominately male arena. If you have an opportunity to watch Home & Garden Television, PBS, or even A&E on Cable TV, you'll see an excellent mix of solo males and solo females, and combination teams as well. I happen to know very competent women who are a carpenter and a plumber. And women are certainly architects, engineers, and designers, and so on. You will begin to see this more as you become more involved in projects around the house. If you go to Lowes, Heckinger's, Home Depot, and Builder's Square, you'll find women working the plumbing, electrical, hardware, etc., etc. isles. So don't let the male-thing get to ya. You are probably being taken a bit advantage of because you are embarking in an area in which you're completely new to, and whoever you're talking to can sense this. I'm sure you've heard about how women are treated in the auto repair industry AND in the auto sales industry. They say, "If you can't dazzle them with brilliance, then baffle them with B/S." You're caught somewhere between the 2. And when you read what I've written below, when I refer to 'him' that because I don't want to say he/she or just she when, like you say yourself, chances are, it's not a 'she'. Now to help you out (as I try to do regardless of sex, race, religion, etc., etc..) :-)
There is the General Contractor, the Contractor, and the Builder. A GC is most-likened to a conductor in an orchestra. He tells the plumbers when to lay pipe, he tells the electricians when to lay wire, and the carpenters when to nail (to name a few). These Sub-Contractors can work for him directly or he can 'sub-contract' the work out to a completely disjointed company.
The Contractor is usually someone (or some trade) that specializes in a particular trade. He can specialize in multiple trades too. A single Contractor can be an Carpenter and an Electrician though not very common. Most Contractors have a speciality (some licensed, others not) but can perform work in other trades. That's why you see a Contractor advertising his work in multiple trades. There are a few other scenarios which I'll spare you.
The Builder is usually someone who builds from the bottom up. Like in your case, the Builder normally would build houses but he's willing to do just the addition too. All he does is, say, build houses and parts of houses, AND he can act as a General Contracator or Contractor at the same time. His 'help' may work for his company directly or work may be sub-contracted out to someone (or some company) NOT directly associated w/his company. So how can anyone disagree w/you when there's all this overlap???
An Architect, like in your case, would design your addition; not build it. They can have a Civil and Electrical Engineer (to name a couple) working for them. Or, he can sub this out. He more than likely will have a Designer working for him too.
The Engineer us usually specialized in an area such as Structural, Electrical, Geological, and so on. If you were building a beach house in Malibu, you'd need a Geological Engineer to sign-off on the fact that the contractor who drilled through the sand DID in fact hit bedrock. Why did someone have to drill 30' to bedrock on the beach in Malibu? Because the building code requires a foundation footing (or house 'leg') be resting on solid bedrock in case of an earthquake. And this footing must be steel-reinforced. The code requirement also states that a licensed Geologist must do the sign-off.
You're feeling more confused than before I started, eh? Well, I've been a goldfish in a peranah pool before but to survive, try to act like a piranah. When you're presented with something you don't understand, look like you know what the person is saying and say right back, "Why's that???" Put an expression on your face too! "Oh yea. Why's that???" I would have to believe that there are books out there specifically for women on this subject as well. AND men for that matter. Go to Borders, Lauriet's, or Walden Books to see what's there. Ask the counter folks for help. I know you're gonna say, "Yea, right!" at this next suggestion but the next time you're out and driving around and you see a home that's being built, stop and ask if you can take a look around. You're just being curious. There's a lot to learn if you were to just watch a home or an addition of ANY type being built! This is how ideas are born!!!
I do wish you well but the straight advice is to keep asking questions but perhaps instead of asking them in the 'frustrated' tone, try the "I know what you're talking about but 'why'" tone. My best to ya and I hope others, especially women, share their views.