Hi, thank you for your question. Just a bit more information required to fully assist you:
-Are you in England or Wales?
-Are you named on their birth certificate or were you married to the mother?
-Are there any court orders in place, if so what?
-What are the exact arrangements?
-From where to where does she seek to move?
If she wished to relocate within the UK she would need to consult you of this as you have parental responsibility. If her relocation would drastically impact your contact arrangements and require them to be enrolled into new schools then you would have grounds to apply to court for a prohibited steps order to stop her relocating, as well as a child arrangement order to have the current arrangements in an enforceable order - both these applications can be done on Form C100 and a £215 court fee.
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