Is a 20 dollar gift card to a favorite coffee joint an appropriate amount for a thank you to a coworker who saved me at least 90 minutes of work today by coming up with a solution she totally didn't have to do?
She kind of humorously said I should buy her a drink from the place and I wanted to but then my day went sideways and she went home before I could ask her what she wanted and I don't know when I'll be back in this office.
If it's American dollars I'd go with ten, but if she balked at accepting twenty I'd tell her to buy something for the office to share, make it a nice morning tea