We have an interesting discussion that takes place in the Cepher Bere’shiyth (the Book of Genesis) concerning Rachel stealing idols.

Bere’shiyth (Genesis) 31:17-19
Then Ya`aqov rose up, and set את eth-his sons and את eth-his women upon camels; 18 And he carried away את eth-all his cattle, and את eth-all his goods which he had gotten, the cattle of his getting, which he had gotten in Paddan Aram, for to go to El-Yitschaq his father in the land of Kena`an. 19 And Lavan went to shear את eth-his sheep: and Rachel had stolen את eth-the Teraphiym that were her father's.

Why on earth would Rachel steal the Teraphiym (idols) that were her fathers?  Was she too an idol worshipper?  Let’s see what happens here when Lavan catches up to them.

Bere’shiyth (Genesis) 31:27-30
Wherefore did you flee away secretly, and steal away from me; and did not tell me, that I might have sent you away with mirth, and with songs, with tabret, and with harp? 28 And have not suffered me to kiss my sons and my daughters? you have now done foolishly in so doing. 29 It is in the power of my hand to do you hurt: but the ELOHIYM of your father spoke unto me yesternight, saying, Take heed that you speak not to Ya`aqov either good or bad. 30 And now, though you would needs be gone, because you sore longed after your father's house, yet wherefore have you stolen את eth-my elohiym?

Ya’aqov’s answer would be quite risky, if he had known that Rachel is the one who took them.

Bere’shiyth (Genesis) 31:31-32
And Ya`aqov answered and said to Lavan, Because I was afraid: for I said, Perchance you would take by force את eth-your daughters from me. 32 With whomsoever you find את eth-your elohiym, let him not live: before our brethren discern what is yours with me, and take it to you. For Ya`aqov knew not that Rachel had stolen them.

Rachel, of course, had already discovered a way to hide the Teraphiym from her father, and she succeeded.

Bere’shiyth (Genesis) 31:34-35
Now Rachel had taken את eth-the Teraphiym, and put them in the camel's furniture, and sat upon them. And Lavan searched all the tent, but found them not. 35 And she said to her father, Let it not displease my lord that I cannot rise up before you; for the custom of women is upon me. And he searched, but found not את eth-the Teraphiym.

While this tells us the story, we get a more complete discussion in the book of Yashar:

Yashar (Jasher) 31:40-44
And Rachel stole her father's images, and she took them and she concealed them upon the camel upon which she sat, and she went on. 41 And this is the manner of the images; in taking a man who is the firstborn and slaying him and taking the hair off his head, and taking salt and salting the head and anointing it in oil, then taking a small tablet of copper or a tablet of gold and writing the name upon it, and placing the tablet under his tongue, and taking the head with the tablet under the tongue and putting it in the house, and lighting up lights before it and bowing down to it. 42 And at the time when they bow down to it, it speaks to them in all matters that they ask of it, through the power of the name which is written in it. 43 And some make them in the figures of men, of gold and silver, and go to them in times known to them, and the figures receive the influence of the stars, and tell them future things, and in this manner were the images which Rachel stole from her father. 44 And Rachel stole these images which were her father's, in order that Lavan might not know through them where Ya’aqov had gone.

Now, this description also comports with the Targum Jonathan on Genesis, Chapter 31, where it is written:

And Laban had gone to shear his flock; and Rahel stole the images. For they had slain a man, a firstborn, and had cut off his head; they salted it with salt and balsams, and wrote incantations on a plate of gold, and put it under his tongue, and set it up in the wall, and it spake with them; and unto such their father bowed himself.

But was Rachel an idol worshipper engaged in the necromancy of Lavan? No. She removed the idols in order that Lavan might not know through them where Ya’aqov had gone.

With the testimony of two witnesses . . . the matter is established.