The simple translation of Gen 32:22 is 'And he rose up that night, and took his two wives, and his two maidservants, and his eleven sons, and passed over the ford of the Jabbok.' That's how the King James edition has it. Darby and the NIV, too.
The Midrash, however, takes the word yeladav not as sons, but as children. This creates a question. By now, Jacob had 12 children (eleven sons, and one daughter) If only 11 crossed the Jabbok, someone is missing. Who, and why?
'Dina,' answers the Midrash, 'Yaakov locked her in a box to prevent Esav from setting his eyes upon his daughter and seeking her hand in marriage.'
A reasonable decision,the ordinary twenty-first-century parent might say. The family was entering a dangerous situation. Eisav, no kitten in his own right, was with 400 soldiers. A young virgin like Dina was especially vulnerable. In the box she was safe. Orthodox Jewish parents, too, are likely to agree with Jacob's decision. Eisav was not only a dangerous man, but an evil man, capable of corrupting the purest soul. In the box Dina was safe from his influence. Entire Jewish communities -from Lakewood to Betar - are built on similar principles.
The Midrash, however, does not approve of Jacob's caution, and chastises him severely. According to the Midrash, Dina's later rape and abduction was Jacob's punishment for not realizing that Dina might have had a positive sway on his brother. For denying his brother even a possible avenue to repentance, Jacob was punished, as the Midrash records: 'You did not want her to be taken by a circumcised man; she will be taken by an uncircumcised man. You did not want her to be taken in a permissible manner; she will be taken in a forbidden manner.'
Remember that the next time you fret about letting your children play with kids from less observant families. Or the next time, you think that your current shul might not be holy enough for the likes of you and yours.