Don't get stuck for too long. She might be indeed to busy and other situstions that have happened in those 4-6 weeks are probably occupying her mind. However, you'd like an answer and I would only try one more time before giving up. In case you worry that she might think that you are still taken, be open about it (you're both grown ups) and text her something like "You know, our encounter and the aura you had, unexpectedly left a positive impression on me. I'm still up for meeting with you, as for your suggestion. In case you aren't far away yet, a cup of coffee would be nice. I'll leave it up to you. In case there is no chance, at least it was nice meeting you and wish you much luck in the future."