I have stated this before on the pink board back when I w3as an every day poster (was kcjones) but I think the bruises are hematomas from infiltrated IV's and from settled blood from the stab and neck wounds.
I have seen (I am a veteran ER nurse of 7 yrs) bruises that big and black from badly infiltratd IV's many times. I have also seen amazingly strange blood settling from wounds that bled under the skin. The way darlie moved around after cutting herself could have caused blood to bleed into surrounding tissues in weird ways. There is no limit to haw far blood can settle and leave horrendous looking hematomas. After Jaw surgery, I had a large blood clot in my face, it rupturede while I was sleeping without me knwoing it, I had blood outward, but most of it seeped into surrounding tissues. I kid you not when I say that I had a coaster sized hematoma over my bellybutton in about 2 days. When i asked the doc he said, "oh that's from the blood in your face, it just settled." It was black as pitch and too forever to go away. How many of you have had blood drawn, and ended up w a huge black bruise a bit further down from the puncture a couple days later?
I would not have put it past Darlie to have injured her arms at a later date, but I have always thought most of those hematomas were settled blood from the neck wound and the arm wound.