if you look pretty carefully at the photos of sheila with the socks lying beside her, there were TWO photos taken (with her hand moved between photos.)
Now, the hand was moved for the purposed of being able to photograph the inside of her arm (which otherwise wouldn't be captured by the camera, so let's not question this aspect of the photos).....
Anyway, I draw your attention to the actual socks:
1) The socks appear to have slightly different levels of staining on them between photos - either a trick of light, absorpsion of still wet blood? or some other issue.
2) They do appear to be heavily stained.
This aspect holds some grounds for intrigue, not least because other blood stains around the socks are consistent with spatter (numerous tiny droplets), and yet the socks themselves have an entirely different form of staining. This MIGHT be due to different material between carpet and socks, but still, the socks (to my mind) look very bloodied (assuming the stains are blood, and not just creases/other stains).
If we assume they are bloody stains, how did they come to be so stained?