I do mean less than 50%. Something below 10%, even. I'm just quite confident that someone who is cryopreserved, especially recently, still contain enough information to be reconstructed. On the other hand, I don't know enough about the physical structure of the human mind to be completely sure. I'd say most of my probability for her being actually information-theoretically dead lies in my ignorance of the subject.

Anyway, that's about 90% of her being still alive. My probability that she will be revived eventually is much lower, of course. I have to account for existential and catastrophic risks, the economic collapse of Alcor, the failure to further our technology… Heck, some religious fanatics may bomb the place for all I know (that one is below 1%).