It will make absolutely NO difference to the ECO in determining the end result of your wife's visa. MY wife, like Mick's, had HER maiden name in her passport at the time SHE applied for her spouse visa [still has] and was assured it would be alright to have it updated to show her married surname once she was settled in the UK.
But just bear in mind what Mick said about booking your wife's plane tickets in accordance with the particulars that appear on her passport at present.
Good Luck!![]()