The charges relate to four different girls aged between 3 and 14 in various locations including Palmerston North, Waikato and the Bay of Plenty.
The Crown argues that Rose offended with Williams by sexually exposing young people and grooming them for sexual acts to be carried out by Williams and on occasions together.
In her opening statement, Crown prosecutor Anna Pollett said a complaint was laid in March last year in relation to the couple sexually assaulting two children in the Bay of Plenty on numerous occasions in early 2019.
A police search carried out at the couple's Cambridge property found boxes of sex toys, childrens underwear including some with the crutch removed, pornographic DVDs and CDs and devices such as laptops and iPhones which showed the sexual exploitation of children and young people by both Rose and Williams, Pollett said.
The explicit images are to be shown in a closed court during the trial.
Pollett said the footage would show that Rose actively took part in some of the offending by holding the girls legs open or encouraging them to get involved, while in others she simply filmed the act or had a role of distracting the mother of the youngest girls so Williams could sexually assault them.
Rose's lawyer Philip Morgan QC told the court some charges appeared to be duplicated especially in regards to those linked to a teenager during 2014 and 2015. While his client had pleaded guilty to four charges of inducing a young person to commit an indecent act in relation to that person and would be sentenced next year for them, he believed some of the other charges related to the same offences and should be withdrawn.
In relation to the charges linked to sexual violation by sexual connection, his client would argue that the teen had consented to it and this was a defence in relation to certain sexual conduct under the Crimes Act regardless of age, he said.
Rose had also pleaded not guilty to a charge of raping the teen and would argue she was a reluctant spectator and compelled to film it.
Morgan said the defence's argument for the other charges was more straight forward and while Rose admitted participation in some of the acts it was her defence that she was compelled to do it by her long-term partner Williams or wasn't present while the act was being played out.
During the trial, 23 witnesses will be called, including one complainant.
The first witnesses to take the stand today were police officers who carried out the search warrant at the semi-rural Cambridge property.
The trial will continue on Tuesday.
