She have had her passport already and your still about to get married?
Yes she can apply as spouse visa, then ammend her passport with married name in Phil embassy in London.
Or ammend her passport first before she apply. Here's the details http://www.dfa.gov.ph/consular/passport.htm
1. Wedding, then wait for the Marriage Contract (MC) in Security Paper issued by the National Statistics Office (NSO) or CTC issued by the Local Civil Registrar duly authenticated by NSO
2. Ammend her passport
3. Apply for spouse visa
Simple as that
