Possibly you're correct. Even so ... the nearest she's ever got to saying she's not a Muslim is to claim to be a 'fire worshipper'.
... which is ridiculous, in this day and age .. she might as well believe the Earth is flat.
Farah, to my knowledge, has never categorically denied she's a Muslim. However, she thinks and acts as a Muslim would. Her hatreds are totally compatible with the worst extremism Islam has to 'offer'.