Well, she did steal chachamaru's drink. Chachamaru is a robot. Maybe she was drinking some sort of lubricant (motor oil?).
What is this!?This is nasty!Master, you cannot die from that...Remember how you're a vampire.Ah...It's my coolant for absorbing heat. Ninety percent ethylene glycol......Am I going to die? Will I die from drinking that?We need to get to the Poison Control Center right away...