Releasing helium balloons is environmentally irresponsible. 

First, helium is a non renewable resource. The atmosphere is currently being depleted of helium at a rapid rate. Medical equipment suchs as MRIs, ventilators, etc rely on helium to run. Personally I think a baby on a ventilator is far more important then a balloon release. What do you think? 

Second, releasing balloons is essentially littering all over the world. How would you feel if people just came by and threw trash in your yard? You probably wouldn't like that one bit. So please don't litter in ours!

Third, every year thousands of animals die a a slow painful death after swallowing balloons. Even bio degradable balloons don't actually degrade. They just break into smaller pieces affecting more animals. Endangered animals such as sea turtles, birds and mammals swallow or get caught in these balloons and starve to death. 

Fourth, you plan on stuffing the balloons with paper notes adding to the litter.

I too have Turners Syndrome so I am sensitive to your cause to raise awareness for this congenital syndrome. However I do not think it's ok to harm the environment to support your cause. I ask you to please reconsider the balloon release part of your awareness walk.