Not sure, but *think* you need another tree in order for yours to bare fruit. It's that whole male/female thing. ;o)

I think different trees have different chill hour requirements as well. So it depends on what the minimum chill requirements are for the Pink Lady variety.
I found the TAMU website that has some good information about apple trees, don't know if it will be of help or not.
Susan

Here is a link that might be useful: TAMU

From what I gather, the Pink Lady has a chill requirement of around 200-400 hours, and is one of the few apple trees that is self-fruitful. You should get a good crop off of it sometime in September, assuming that your tree has reached maturity.
According to the information that I could find online, the fruit develops the best flavor with exposure to sunlight, so there will be a lot of pruning necessary, and it develops the best color with a good chill.
Check out the link below for more info.

Here is a link that might be useful: Pinklady Information