Opinions of parents are divided over the controversy that has engulfed Burwood Girls High School and its planned screening of a gay parenting documentary.

Today NSW Education Minister Adrian Piccoli was forced to step into the debate and he directed the Sydney school to shift the showing of Gayby Baby to after-school hours – not during class time as had originally been planned.

One woman told ninemsn that her younger sister, a Year 12 student at Burwood Girls High School, has been bullied by teaching staff and students for choosing not to take part in the school's voluntary Wear it Purple day – a celebration of LGBT pride.

The film Gayby Baby, which follows the lives of four children being raised by same-sex couples, was scheduled as part of the school's Wear it Purple program.

"Last year [my sister] chose not to take part in these [Wear it Purple] festivities and teachers were questioning her and telling her it was something that she needed to do," said a woman who identified herself only as Josephine.

"I'm outraged, because my sister is being bullied for having her Christian ideals. She's not a very outspoken young lady and she still feels bullied when she doesn’t partake in this event.

"Everybody has the right for freedom of speech," said Josephine, who is also a teacher at a Sydney high school. "Students, such as my sister, who sit this out shouldn’t be discriminated against."

But these claims jarred with the assertions of Maree Gemmell, mother of a girl who is a school captain at Burwood Girls High School.

"The girls don't have to wear purple if they don't want to. It's a fun thing, a mufti day," said Mrs Gemmell.

"Burwood Girls celebrates so much diversity and the acceptance of all people. It's not one group of people. Everyone is accepted. This is why it wasn't really an issue for the girls to see this movie."

Mrs Gemmell said she was disappointed that the screening of the movie had been moved to after-school hours, but added: "I think if anything the girls will want to see it more now."

The school also regularly celebrates the Chinese New Year, various Asian days of significance and an Iftar to mark the importance of Ramadan, said Mrs Gemmell.