Quoted from Blackbeard:
Trust me, dont do this. Gift cards scream “I gave zero thought” which in turn is interpreted as you don’t care.
Get together with one of her close friends or mom and figure out (if you don’t know) what sorta ring she’d wear, and surprise her.
Also, try to locate said $25 ring as well and incorporate it in Christmas, along with the more expensive ring. Maybe in her stocking.
Go the extra mile here. Woman really notice this crap.
Take heed of the above instructions. It will make everything better.