Q:Will it be possible to register the PS3 version's pre-order bonuses on the Windows version?
A: Yes, this will be possible. By inputting the product code enclosed with the PS3 version into your PS3, you will be able to choose to add the PS3 version to either an existing FFXIV service account or a new FFXIV service account. If you choose to add it to an FFXIV existing service account, the pre-order bonuses will be applied to that FFXIV service account.
So, yes but you'll have the early access and items, not her.