Praise be to Allah the Lord of the Worlds.
The woman observing Iddah following divorce or death of husband isn`t allowed to travel for no necessity, as agreed by the majority of the scholars. Al-Shirbini says: "She isn`t allowed to leave for business, social visits and Hajj, because they aren`t a necessity." {Moghni Al-Mohtajj, vol.3/pp.402}. And Allah The Almighty Knows Best.