Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
How old are the children and are you named on the birth certificate?
Do you know which Church she has approached?
Your ex should consult you about these matters but if she does not your options are limited.
You can apply to the Court for a Prohibited Steps Order to prevent the Ceremony taking place until the court has decided if it is appropriate - you do this using a form C100 and paying the fee of £215.
Alternatively you can make a direct appeal to the Priest of the Church and ask him not to go ahead until you have discussed the matter
I hope that this is of assistance - please ask if you need further details