Ok so when the quest i could make you care starts and i tell her that i have things to do she says that she'll be back in hidden vally buncker. But when i go there i cant find her. So i went to the 188 and the lucky 38 and sges not there eather. Does any one know where she is???

She glitches out sometimes. I generally just fast travel to a location closest to my current location on the map, then walk back to the bunker. She's usually there, in the computer room outside of McNamara's office.

If you still can't find her, go to the Gun Runners Arsenal or the lobby of the Lucky 38 and use the companion dismissal terminal and dismiss all companions. You should then be able to find her where you first met her.

I have gotten in the habit when doing companion quests of either keeping them with me until they are done, or taking them to where I want to dismiss them to, save, then dismiss them and see if they are where I told them to go before moving on.