You must verify the situation yourself. If there is anything sensed then you must bring her back with you to the UK. BUt you should undesratnd that this is a Grave accusation and you mut be very careful in using such terms.
For further explanation, make sure you remind your wife that your father's her Mahram and can for that matter kiss her or touch her just like he would do to his biological Daughter.
So you must be extremely cautious in judging this.