Demons like Etrigan are weak against iron and Raven is half demon, so is it possible that she could be weak against iron as well?

Does that count for all classes of the Demon Heirachy?  Cause as Raven is decendant of a Demon rather high up the ropes, it may not affect her.  Plus her hybrid biology may negate any affects a demon of her level would be afflicted by.  Alos how does a demon with iron weakness handle human blood? Would it hurt them?

Never seen her have any iron allergies, but as Beast mentioned, she's got iron in her blood so its doubtful.

I would imagine that silver would do the most damage to her, but that is just me.

I'm pretty sure Trigon is an incarnation of evil/alien warlord rather than an actual demon. Darkseid, for example, isn't considered a demonic entity (as far as i know.) It's more like that.

Raven would be as weak to iron as any human, same for silver or any other mineral/element/material.