I have a small issue with my follower lydia. I started the diplomatic immunity quest with her in tow and it obviously won't let me take her with me so my question is where did she go. She is no where to be found after weeks of in game time and she never shows back up at my home in whiterun. I've checked where the quest began and everything and I have no idea where she is at. Does anyone have any advice on the matter? Thanks

Ive lost her one time in my Breezehome. She was in my room, like a [censored]in sneak thief, hiding behind an open door.

She'll be at breezehome (if you have it) or in the Whiterun keep.