So change in thoughts...Daniel drugs her because he wants her dead but the drug doesnt become the cause of death. Lillian potentially struck her with the statue during their argument over the papers to which Evelyn burns them during the same argument. When Lillian leaves to go upstairs it might be to talk to Claire about their argument. When the crash happens at 1030 it could be Evelyn alone passing out from blood loss and the drowsiness from the meds, upon which she strikes her head on the fireplace ultimately becoming the fatal injury.
Daniel Mercer
Lillian Vale
Thomas Reed
Marcus Hale
Claire Blackwood