You just recruit Vanessa.You noticed that it has a small health problem:
She falls.
You must find a clue about what is happening. This clue is on her: a lettre 

Heart Shaped Box
Take that letter in his inventory. This letter is intended to Jessi.This letter explains her problem and activates the first quest.
This quest sends you find Arcade.
Arcade has in its inventory a book. To access to its inventory, very simple, hire him!
If ever Arcade died or lost ... there was another book hidden in Nellis.
Once you have the book, you get a note. This note send you look for a new heart.
Go to the kitchens of The UltraLux, take the heart.Once you have the heart, go see the Doc Mengelele in Cerulean Robotics.
After changing the heart, talk to vanessa.
This will activate another quest.

Take Her for a spin
Go to the atomic wrangler, buy 2 beers at francine garret.Give a beer to Vanessa, she will sit at a table, follow her and sit.Talk to her, she will tell a lot of stupidity and then offer to sleep with her.
You will not have to choice but to say yes.I know this is tough ...
I'll add an option in the next update.
Then go to the room of the atomic wrangler.
In this room: Or Vanessa adds a script package, or just talk to her.A small stage begins.Once this stage is completed, talk to Vanessa.
This will trigger the next step of his quest.Then you go In the Mojave Outpost.You buy a dress named Vanessa Dress.Give it to vanessa via the options dialog.
Then talk again and invite him to the restaurant.In restauarant, she still tell you stupid things as only her is able to say.And she proposes, with words to her, to become her girlfriend/boyfriend.
If you choose yes, a new letter appears in one of the inventories.Take this letter. This will activate the quest Ring of Fire.
Now she can heal you, you can change her armor.
If you choosed to be her boyfriend/girlfriend, she can get naked --> Now you can give her the outfits you want.

Ring of Fire
This letter indicates that a recipe to create Molotov is available.Go get this book.Give a vanessa via the wheel.Once the book in her inventory, a new dialogue line Appears in menu / weapons / molotov

Increase Vanessa Skills (3 quests: guns, repair and Sciences)
First with books, Then teacher yourself. (skill 80 minimum)Once completed this, it REALLY Increases her skills.Now she can repair your stuff / create new items.

There one last quest, but this quest is implied.
You must find out who is the sister of Vanessa.There is so much evidence that c is so easy :)