I thought that must be the case baw70.
Her going on the run in contravention of a court order is clearly the action of someone in severe distress.
As far as I understand it the mother in this case is the childrens primary caregiver, and the children have said they don't want to go back to Spain. In most cases the Hague convention does not consider the children's welfare, only where their country of habitual residence is. I think the original purpose of the Hague convention (which was to protect the children's welfare) has been lost in its application since the concept of it originated.
There are many primary caregivers 'trapped' in other countries away from family, friends, and much needed support because, sometimes, the Hague convention is abused. On solicitor I spoke to said in 90% of his cases, the Hague convention was being used as a means of continued domestic oppression.