Thanks MalcolmB.
We've booked in a 9 am, so hopefully we won't have the backlog issue. I have a day off work anyway, and I've always wanted to spend time in Croydon ;-)
We are meant to be going out to the States for a week around 3 weeks after her appointment. From what I've seen on delivery times, we should have it back by then. My only thought was: if we have't got it back, she could head to the states without me (she has plans to go earlier than me anyway), and I could wait to receive the ID, and take it with me to the States. She'll then have it for her return to the UK.
Re ID: what is acceptable? Passport, bank card, driver ID, anything else?