What a crazy coincidence: I was reading the Betsy Ross and the Silver Thimble book to the girls last night (it was Flag Day) and was disappointed that exactly this was written in the book: "You do not know how to use Father's tools. A saw is not for a little girl," and then the mom gives her a thimble... Seriously???
This is a toughy! I've homeschooled my girls so far through preschool and we're starting HS Kindy this Fall. Even without much external influence, one of my girls said, "Girls are nurses, boys are doctors" the other day. I was stunned! (When we asked her how she came up with this perspective, she said, "The Playmobil figures." (I come from a long line of career women--and had a very successful vocation of my own prior to seeing the brighter side of the world with my children as a stay at home Mom). So, I think it's difficult (although doable) to balance all the external inputs which shape the children's viewpoints.
I agree that it would be wise to ask questions around the American Girl curriculum. I have done all I can (and been successful so far) to avoid the commercial American Girl toys. I even "disappointed" relatives in NYC last winter when I refused an invitation to take the girls to whatever that tea party is. I'm totally on your side.
Also, I have found an incredible artist who mentors young children (read: sits down and does artsy things with the girls while I catch up on bills and other misc. house stuff). I've specifically asked him to do a summer-long project with the girls building a treehouse in our backyard. I WANT the girls to do woodworking (I once built a fence and found that incredibly gratifying). Our art tutor uses wood with them in projects and will help them learn how to hammer and use other tools this summer. Maybe you can find someone to do the same with your girls? Even the instructor that has all boys in that woodworking class? Our art instructor is a male and I always make sure they are in my peripheral vision/within earshot because I am that concerned about even "trusted" males around my kids... Still, I hope you can find someone to do the woodshop activities.
Hang in there! You'll find the right balance for your family!