I'm glad you have a lawyer and you're following their instructions. I'm really glad that you have someone to talk to who is supportive of your feelings.
I don't know you, and I don't know your practice. Not checking a blood sugar within 15 minutes (unless you failed to check it for several hours) is a "so what?" sort of mistake. On an insulin drip, it would be a big deal, but not TPN. Wrong fluids -- also probably not a big deal if you caught it within 20 minutes. The insulin pump -- not sure I understand what the problem was there, if you overlooked that she HAD an insulin pump or what. But it doesn't really matter to my point.
My point is that more new nurse and nurses new to a particular job fail in their orientation because the established staff doesn't LIKE them than for any other reason. Often times it's just because the new person is anxious and too focused on the tasks to take time to be LIKABLE. I know this because I was that new grad who was nearly run out of my job and my career.
If people LIKE you, they will cut you some slack, even when the errors are huge. If they don't like you, you will wind up in all kinds of trouble even for minor errors. The takeaway is that you want people to like you. So, while you are at work, you pretend to be an extrovert; you act as if you like everyone you encounter and are thrilled to see them. You smile and say hi to everyone, every single time. You take 30-60 seconds to ask them about their commute or their garden or their dog or their kid every single day, even if you don't really give a crap. You introduce yourself to everyone until you are positive they know your name. That's hard work, but it is part of the work of starting a new job.
Trust me, I don't like this either, but it's the reality.