Very nice specimen you have there. If you are feeding frozen thawed maybe you could try to heat the rat up a little more. You could also try just putting it up to the side of her face and just let her crab it. This way she will not have to strike out at it.
You could also try waking her up with a food item before she gets in the hunting mode. She will be half asleep.
When an emerald strikes and misses its prey it can be serious. If she hits an unexpected hard object she could break her jaw. If she breaks her top jaw she will probably perish.
Hope this helps.
Ed Marino
www.EmeraldTreeBoa.com