Settlement visa wife commonwealth

My wife visa was approved and she was supposed to come to the UK between 08 August and 08 September but she could not make it because she's pregnant n the airline Wouldn't allowed her to travel coz of her condition. She just given birth n she won't be travelling till shes fit to travel. Her visa is expired since she supposed to pick it up between 30 days . It's the 12th September now and her visa is already expired is she still can apply for a vignette transfer visa to extend her visa sinces it's already expired I need help pliz

She can apply for a new 30 day visa vignette, costs £168.

So can I apply for more than 30 days coz she will be fit to travel than ? And how does it work to apply for it do I have to send more evidences or document when I apply ? Thank you.