Who is Fela, and what does she do to incite Dedé’s anger?1

Fela was an old servants who claimed to have had the ability to channel Dedé's sisters' spirits after they died. Minerva's daughter visits Fela to talk to her mother in the spiritworld. Dede thinks this is disrespectful. Dede does not like Fela telling Minerva's daughter details of the past.