Praise be to Allaah.
It is not permitted to enter the bathroom with anything that has aayat
from the Quraan on it, because this could lead to disrespect of the Word of Allaah,
may He be glorified and exalted. Therefore, your wife should remove this necklace before
entering the bathroom. Our advice is that women should not wear any jewellery with aayaat
or duaas on it, because there are a number of reservations about this
practice, of which wearing it when entering the bathroom is just one.