Would it be inappropriate to get my manager a small gift given my circumstances?

I work in a small spa attached to a medical practice. We have largely been ignored as far as getting new supplies, new training, advertising, etc. A year ago, we had a fellow employee get moved up from a general position within the practice to a practice manager position. It was out of the blue, and a lot of people were not thrilled about it. She was not my direct manager, her co manager was, but obviously being a practice manager, we still worked closely with her and she was still our superior. Her co-manager has since left, so she has become my direct manager. When I tell you this manager has gone to absolute bat for our department, I’m not exaggerating. The company has been in chaos these past few months, with a majority of things falling to her, and she has still gotten me everything I’ve asked for to get my job done properly- additional admin hours, a marketing team, product refresh, training. Things that I have been asking for for years and never received. I’ve now been given the proper tools, time, support that will lead to me being more successful in my position.

I would like to find a good way to say thanks, that is appropriate but also shows just how thankful I am. I don’t want to come across as kissing ass, because I’ve got exactly what I want and have zero requests left, but I do want her to know her efforts haven’t gone unnoticed. Prior to her becoming a manager, we were on the same level, just different departments, and did have somewhat of a rapport. We’re the same age, if that matters.

Would it be inappropriate to gift her a box of pastries or a small desk airplant? A card seems too formal (and too kiss ass)- not sure what I would even write in there past “thanks”.