My understanding is that folks fall on both sides of the fence: just as many with appropriate family cancer histories choose to test as those who choose not to, very similar to your godsisters' individual decisions. Knowledge can be a powerful or a dangerous thing, much of that depending on the nature of the person holding the knowledge.
I have a family history of pre-menopausal breast cancer (grandmother and sister), but I have not pursued BRCA testing thus far although I have considered it and may choose to test in the future. The reason I had chosen not to test initially when it was offered a few years back was that I didn't think it would matter for anyone other than myself as I have no daughters (and am almost past child-bearing age), and my sisters are not interested in testing. What has caused me to reconsider of late is a couple of factors: learning that BRCA genes can also impact men as well as increase their chances for early colon cancer and therefore concern for my son, and a BIRADS 3 finding on my most recent mammogram has kept it a possible consideration.
Though I currently don't have any problem getting yearly mammograms covered by my insurance, the recent government recommendation that they need not be performed but every other year is something I'll be keeping my eye on. If it comes to pass that my insurance declines to cover annual mammograms, that may be a crossroads point at which I would pursue BRCA testing to ensure that 2 year interval mammos are adequate. Hope that answers some of your questions... good luck with your paper! ~eureka
PS: There's also an active Breast Cancer community that might give you good feedback:
http://www.medhelp.org/forums/Breast-Cancer/show/54