This is such a sweet story and you guys sound so cute. Your determination in asking Miki & her helping her to find something and someone she loves is not only funny but inspiring. I know that, as her boyfriend, you want to make her feel loved and safe, and so, with the most respect for you and your relationship, I really want you to consider if this is a good idea or not. Public proposals are very cute but they put a lot of pressure on the girl and can be very intimidating. If she maybe isn't ready to commit to something as huge as marriage, being asked to in front of thousands of people could be very scary, and even more so because she has an anxiety disorder. I get that you want to make it very special and that's so kind of you, but please make sure that this is the right decision for the both of you. Maybe ask her beforehand. It may not seem as romantic, but I think she would really appreciate it. I'm not trying to kill the mood, I just want you guys to happy. Wishing you the best of luck.