We're up on the 8th floor. I just won't risk it. One Saturday, when I was house cleaning, and I thought she was sleeping under the bed, it turns out I had left the balcony screen open a crack, and she had been lying out in the sun for 3 hours! Even still...
I go with better safe than sorry. Some of your pictures look like you are really high up if she were to leap after something. Cats in general and especially young cats are incredibly fast.