I'm not quite sure what your question is , but if you both have British passports then you do not have a problem entering or staying in either Spain or Gib.

Kyle, if the following is the case, the UK including Gibraltar is not committed to the requirements of the Shengen list?

http://en.wikipedia.org/wiki/Schengen_Area

Maybe she could come with you under the concessions for unmarried partners of British Citizens.

http://www.ukba.homeoffice.gov.uk/policyandlaw/immigrationlaw/immigrationrules/part8/unmarriedandsamesexpartners/

'Hope it helps & good luck to you both