Everything unionreally wrote is true. That said, it is also true my college roommate dragged his girlfriend up Mt Blanc with us when we climbed it some years ago. The problem is crossing the glacier. Unroped solo travel across the crevasse field is not advisable. You could hire a guide. Or, fall in with some Brits in one of the many bars in Chamonix, buy a couple rounds of drinks and try to talk them into joining their rope across the glacier.