I'm not one of the fellas, but here's my 2 cents:
You may be clear about the fact that you don't like her like that. She may be just "One of the girls", in your eyes. But if you're not 100% sure that she sees you as a friend, and only a friend... It's probably not a good idea to send her anything. Just tell her how much you appreciate her friendship and leave it at that.
If she does have feelings for you, and you know it, you'll be responsible for leading her on. Knowing that you're not interested. Then you'll be left wondering how to get rid of her, and the whole friendship will be ruined.
If the two of you are on the exact same page... I think it would be fine to show your appreciation with gifts.
I have a guy friend who's really cool. We talk, laugh, and he's alot of fun to be around! I enjoy his company, but I'm really careful, because even though he does his best to hide it... I know that he likes me. But I see him as nothing more than a friend and brother in Christ.
So it's my responsibility to protect him. In doing so, sometimes I want to do kind things, or say hey let's go to the movies because he's my friend. But I refrain because I know it would be misread and give false hopes.
We are our brothers keeper! God would hold me responsible if I send this man mixed signals and lead him on, knowing where we both are. That wouldn't be right!
Having given my speech, and one of my stories... I do understand that you just want to appreciate a good friend for her kindness, but be careful!