Yes there certainly are rules.
As part of the prosecution process the CPS has to make available all the evidence it has in connection with the matter. This includes all the material they intend to use as evidence in court but also includes any material that may have been gathered in the course of the enquiries even if they do not intend to use it. This is to prevent them keeping back evidence which may not suit their case but which may help the defendant and this is known as “unused material”.
Evidence cannot be produced (by either side) on the day of the trial if it has not been seen by the other side previously. So if this video evidence exists and your daughter’s solicitor has not been made aware of it, it cannot be used. If they intend to use it in such circumstances the prosecution will either have to get your daughter’s solicitor to agree to its inclusion and he would be entitled to ask for an adjournment to allow time for him to do so.