Its not accessory to murder. She would have to knowlingly and willingly dispose of Rudy Guede’s crime. But obstruction of an investigation or making false statements, probably. I believe her mistatements over Patrick Lumbumba could be considered for that, even if she barely understood the Italian language (they should have had an interpreter there, during their 10 pm to 6 pm 3rd world interrogation of her). In fact I believe she was convicted of making false statements and has not bothered to contest that because her time in prison cover time served for that lesser crime.
How do you "dispose of" a crime?
The normal definition of accessory after the fact is someone who helps conceal a crime, fails to fully report it or aids the criminal in concealing it.
By pointing a finger at Lumumba, she enabled Guede to get the drop on the police and flee the country.
Also, an overnight interrogation is hardly a "third world" affair.
Few first world police investigations do without them.
THe matter of having an interpreter is more on point. The police did not understand American idioms.