If you are arriving by train Station Tap, Rutland (treat her to a chip butty) and for retro Fanny's or for modern style the Stancil Brewery place.
If driving stop in Heeley as recommended earlier. There's also that new trendy place where the tram depot was that my missus likes but doubt you will get much pre match atmos.
After match get yourself down Kelham Island if she likes the ale. If not, Ecclesall Road is a bit more bird friendly with wine type options. If she likes a scrap take her pig hunting on West St.
Incidentally, I didn't realise girlfriends meant an anniversary and learning songs. Great lass. Get her married if she gets equal marks in the sack department...
UTB