It's been 17 years and you're selling it now, when you happen to not be speaking to her? I don't know what your property rights are in Victoria, but I can tell you that you shouldn't do it. If you've hung onto it for that long, it obviously has some meaning for her, or you, or both. And that just adds weight to the 'don't sell it' argument.
If you do sell it, I can predict one of two things happening (regardless of whether you have the right to sell it):
1. You and your sister will reconcile, but she'll be angry at you for selling it - which will degrade your relationship; or
2. You and your sister will not reconcile, and she'll be throwing blame at you directly and through the family until the end of time.
Unless it's somehow going to change your life dramatically for the better by selling it, neither (1) nor (2) are worth it in my opinion.