First congratulatins 1 more year more its your silver anniversary..its a gift from above indeed.

i suggest do the uniquely way ...not expensive ...simple but very loving way that u never deed b4.

take her t o a church a pay for thanksgiving mass
in the evening take a walk in corniche,take a dow ride ..then take simple dinner along that corniche if any...before it everthing ends ..just affirm to her your love for her and say "happy anniversary " and i love you so much.
im sure she will never forget that thing in her entire life...its simple/loving yet not expensinve

congratulations.....