Exactly!while you may have good intentions for leaving her on your balcony, puppies are like little kids, if they aren't supervised, they are going to get into all kinds of trouble..
She has to be watched at all times when she is out and about. If you cannot watch her then she should be crated for her safety and for your sanity.
Puppies are ALOT of work, they chew and bite and get into everything, it is your job to make sure she only chews on her toys, it is your job to redirect her when she bites and it's your job to watch her so she doesn't get into anything that could cause her harm or ruin something of yours.
When she gets passed this stage, you'll be happy you didn't get rid of her and you'll wonder how you ever could have lived without her.