JS, just relax a bit, and apply your better mind, not the monkey-chatter one. Turn off the monkey-chatter. I’m assuming that your dojo is teaching you how to do that. Calm down, use what you’ve been taught. Since the gal in question is apparently learning the same techniques, you have a nice common base of reference.
You gave her flowers; always a beautiful act toward another. She expressed an interest in the Iris farm, so you gave her a gift. If it was too much for her now, just say: “I heard your interest in the Iris Farm, and when I saw those flowers, I wanted to share them with you.” This is the part where you smile bright and honest. If she isn’t interested in a romantic relationship, just smile again, and tell her how much you enjoyed her company at the museum, and would be glad to be in her company again.
If she isn’t interested, so what? Don’t beat yourself up. Don’t attach to it. Since you’re in a dojo, I’m assuming you have a Sensai for guidance. If you are too terrified to open up to another, you need a bit of guidance in order to get past that. Ask those you know, and work on the fear/shyness. Once that block falls, life becomes much easier.
Hope I don’t sound too didactic, but that’s been my experience.