Two Coptic priests have already been arrested, because while 'dawah' (proselytizing) is part of a Muslim's religious duty, converting to other religions is a crime, sometimes punishable by death.
“I understand there was someone from the Arab origin that accepted Christ and was baptized by them,” leading to their arrest within the past few days, one religious leader told AFP.
So two Christian priests are in jail, and some Al-Qaeda linked group calling themselves al-Qaeda in the Nilien States wants that Christian convert back. Probably so they can stone her to death for apostasy. If the Christians don't return they woman they claim was "kidnapped" they will target the Copts in retaliation.