The vet spoke to a rabbit and guinea pig specialist from Sydney who said that a splint should be adequate to allow the leg to heal, and that pinning it held more risk to her. So I went with that option.
I got her back yesterday evening, the vet explained everything to do with her care and I've been given an anti-inflammatory pain medication to give her each day. I need to keep a close eye on the splint and appetite to make sure there's no signs of infection, and for the next six weeks she'll have weekly check-ups (there's no extra cost thankfully) to make sure things are running smoothly. At the end of those six weeks she'll have some x-rays to see how it has healed, and to decide if it's ready to be taken off or not.
He showed me her x-rays and I was right about feeling a deformity and and a "joint" where there wasn't supposed to be one. The bone was snapped clean in two and was quite displaced, my poor little girl.
The second lot of x-rays with the splint on were good, he's managed to line it up near perfectly so he's sure it will heal up really well. Good news, if all goes to plan over the next few weeks! Fingers and toes crossed for her.
She seemed a little shell shocked when I picked her up, but it was her first time away from her mothers (yes, plural! long story - while I was overseas one of my boys died, so my friend looking after them put his friend in with the girls because she was worried with it being winter and all - four girls oh dear! Of course he managed to get all four of them pregnant, haha. I separate them when they're heavily pregnant and as two of the girls were at around about the same stage I brought them both inside and homed them together... I missed the births by a minute at most, and so I had no idea whose babies were whose.) and sisters, and me of course, so she must've been frightened all on her own in pain.
She's settled now, I'm keeping her in a small cage in my bedroom to watch her closely - she'd better not start nibbling the splint! She's getting the hang of moving around with it (she's not allowed to move too much though!) like the vet said she would, and she's such a good little girl for taking her medication with no problems today - I think she even liked it as she wouldn't let me take the syringe away and wanted more! That's even without it being put in a small bit of fruit jelly like he suggested.
Here's a picture of her -
GPG - I've no idea how she was injured, she was fine the day before and then I just found her like that. I doubt she'd be calcium deficient since she's only a baby and was drinking her mother's milk up until a few weeks ago, plus vitamins are added into the water bottles.