Dried cracked blood denotes a thin layer that has trickled and would have been quick to dry rather than a large volume. The warm atmosphere inside the farmhouse would have helped the drying-----plus,in normal,healthy humans,the bleeding time which would have been the normal ratio clotting time ( 0.8-1.1 ) also played a part while she'd still have been breathing,just.
Because Sheila had been supine,the overflow of blood in her mouth would have just trickled each side,obviously while deceased, where the heart no longer pumps.