If your H1 expired, your fiance can't qualify for H4. So she will need to come to US using some other route (H1 etc - don't forget about the cap), marry you, file for her 485, all before the short window to add spouse to your application closes.
If there's very little time left on your H1, then it may be a problem getting a H4 visa based on your almost-finished H1.
If you have any choice at all, you should get her here, say in the next 1-2 months
If you cannot get her 485 to join yours before the window to do so closes, she'll be subject to a looong delay, something probably best avoided.