Kaguya was a Shinobi.

[Solidus Solidus Solidus]

Another definition of Shinobi:
> whenever a clan leader/member decides to leave his/her clan he or she is considered a Shinobi. Someone who betrayed and disobeyed the clan's pride.

And what was Kaguya? She was the leader of the Ototsuki Clan before she left to eat the fruit. Later Kaguya had war against the Ototsukis, why? Probably she was considered a Shinobi who betrayed the clan.

Ty and Kaguya was the only true Shinobi in Naruto ​

 

[nandachikara]

more like a scary obasan who ate the god fruit.

 

[Obito the supreme jin]

Kaguya is a goddess she is way above Shinobi level. She has unlimited chakra and you can't kill her. Shinobi can be killed, she is immortal however because you have to seal her. Nothing about her ever betraying her clan was stated, she was just feared by people because of her powers. She was still part of their clan because Rogue Shinobi doesn't exist within the Oosutsuki Clan.

 

[Slayer of Eternity]

too bad for her, in the end her mistake was getting out of the kitchen.....as usual.

 

[KesOnFire]

Last line is false

 

[Itachi Solos]

Self-sacrifice... A nameless shinobi who protects peace within its shadow. That is a true shinobi.

 

[Blackzoro]

Not even close itachi was the real true shinobi if u deny this u obviously gonna get soloed by itachi tsukiyomi

 

[Melanin]

Lol...