False, you receive a "Blessed Mail Breaker" which has nothing to do with this character's normal Parrying dagger. On the other hand, the weapon probably is a reference to how they fight against sinners, represented as Rosaria's fingers since they are meant to be the invasion covenant.

Unrelated, off topic.

Ds3 is over 2 years old you can’t really get mad

Nothing there is really a spoiler tho

Dark Souls isn't even a series that can be spoiled. It's so convoluted, and most of the story happens off-screen anyway or is just plain conjecture.

dude it was a item drop in a questline

*****

I would like to know if this counts as betrayal aswell

This may be a little late, but no, killing her does not count as betrayal to the covenant. And for the second part of your question, yes you can still join the darkmoon blade if you kill her beforehand.

She is like you forsaken undead, she is not quite, hollow but refuses to allow anyone to see how close she is to being hollow. She is a woman after all, the loathe any impurities upon their body, so it makes sense she would hide such a thing.

Well you can still use the first Bonfire in Anor Londo if you let her live

Once you've killed fatman and tall boy, the optional boss and gotten to the archive bonfire there is no reason to keep her alive.

According to a video by ThePruld she's hollow but still has her sanity like the player character. I wouldn't want people seeing my shriveled body either