The answer to your question Cheryl is NO.
It's really not that much of a quandry imho...the only one to blame for charlie's "death" is eldon styne. He killed her. Show blatantly made it clear at the very beginning of the episode that jacob's murder and the loss of the book must be avenged or eldon would lose his place as heir. Sam, Dean and Charlie were targets. Whether or not she had the book made no difference whatsoever....she found the book in the first place and they knew that ..they were seeking the book and thus discovered charlie because the compass went off ...noone knew the book couldn't be destroyed except the stynes...so burning the book meant nothing as it couldn't be burned...and dean wouldn't give the book to the stynes knowing what they were about, so even if dean knew the book couldn't be burned, he wouldn't have handed it over.
if you think about it, sam bringing charlie to cas was actually more of a benefit to her, because she wasn't alone. She had the protection of an angel and where she was ended up being the safest place for her...because out on her own left her vulnerable...because as i said, she was targeted whether she had the book or not. The reason charlie was left vulnerable once again was because she left the protection of the safehouse she was in, and she left the angel who would keep her safe.
but to blame the death of charlie on her or sam or even dean is a ridiculous notion to me. charlie was killed because unfortunately in the spn world as much as the real world, there's evil....and bad things happen to good people, especially to good people who try to rid this world of some of that evil.
the death of charlie is more meaningful than the unproven hypothesis that show just likes to kill strong women..charlie as with all the women on this show are more deserving than that.
charlie's death was necessary to push moc dean over the edge and advance the story hopefully to it's nearing conclusion.
her death also pushes sam to fight rather than give up. ( i think her email will give him back his will to ensure that charlie didn't die in vain) this ties in with jared and jensen's always keep fighing campaign.
she also represents what's been the mantra of the season....we are stronger together than alone. charlie went off on her own, fell to her old pattern of being a loner and the end result of that act was her death. staying with her winchester family, which includes cas, she was protected and thus less vulnerable.
really charlie represents "our love" for the boys. she like the other's before her are a reminder to sam and dean that they are not alone in this fight. they don't only have ea. other...that there are family and friends who love them and see worth in them....and do for them for no other reason than you do what you can for the people you love.
what sam and dean have to come to realize, and hopefully charlie's death will eventually do this, is that they just have to accept that people love them. They're going to do whatever they feel necessary to help these boys when they need help.....sam and dean just have to come to terms with the fact that they are loved .....
and what they need to do is stop taking the blame for other's love and instead respect it by doing what they do and doing it together.....