Thanks Casa - as ever for you help and advice
The confirmation letter and the biometric letter arrived on Saturday
We went to Manchester Post Office to register her biometric information. However my wife made a mistake signing her name, and the Post Office clerk submitted it before we were happy with it (the booth was dark she couldn't see what she was doing, and the clerk was clearly in a rush to go home as they were about to close)
Could this (or is it likely) to create problems further down the line? Should I call UKVI to say what happened? More poor wife is worried sick she could be denied her visa for such a small mistake and one of which was not her fault