Many things! I once left my injured (lame) mare tired up, tightly, in the stable, whilst I went to call the vet, with her stall guard chain done up, but the stable door open. Came back from the house to find out outside her stable, panicking because her rope was now very tight. How on earth...
Firstly, have you checked her teeth/ back/ saddle first, just to make sure she's not being awkward because she's in pain? As you say she's very green, I'd recommend lots of schooling to get her more responsive, as opposed "sticking a piece of metal in her mouth", so to speak - finding a good...
I did my mare's final clip on Monday. All I did was clip her legs off (she had been hunter clipped since October), as her summer coat is already (slowly) starting to come through on her body.
If your horse's summer coat is already starting to come through, then no, I wouldn't clip, however if...
Oh how sad. I'm very sorry. As the above poster has said, perhaps you should give yourself a bit of time before making further decisions, and then see what you want to do. Many hugs to you at this awful time. x