>>> as well as actually getting the photos she has sign the back of one and sign the application form !
Wrong, as usual, Eddie. If a passport renewal is done online, the applicant has to submit a
digital photo, so there's no 'back' to sign it on (and no form to be signed).
I can see no reason why Zabado can't make an application online for a new passport in his wife's name. Indeed, the website specifically mentions that someone applying on behalf of another adult should answer as if they were the passport holder. The only problem he might have is in intercepting the passport, before his wife sees it, when it's delivered.
https://www.gov.uk/renew-adult-passport/renew