Disabled Discretionary Trust - non-residence problem?

I have been instructed by a couple to set up a discretionary trust for the benefit of their daughter who is disabled (receives DLA care at the higher rate). The father has UK domicile and residence. Mother has US nationality, is unlikely to have domicile of choice in England, but has lived in England permanently for the last 10 years. The trust assets themselves will remain in the UK as this is where the family live. Will we have problems with the trust given the overseas aspects of this case? The intention is that they will set the trust up as a pilot trust now and then transfer their estates into it on second death. Many thanks!

Kathryn Caple
Else Solicitors