A manicure after the massacre.

I'm glad you find this amusing----NOT ! There HAD been time after the murders for Sheila to have showered, put on her night clothes and generally get herself " back to normal " by making herself look presentable after death which included the appearance of her nails. Sheila even had time for a small snack in the interim, as noted by the contents remaining in her stomach of which none were found in the other members of the family.