The school did not indicate how recently infections of coronavirus from attending celebrations had occurred.
From Thursday November 5 until the end of Tuesday this week, weddings were prohibited in England under lockdown rules.
It is now permissible for 15 people to attend wedding ceremonies and receptions in the capital under tier two restrictions.
Dr Tamara Djuretic, public health director for Barnet, said: “It is parents’ responsibility to ensure children are not attending larger gatherings as that can endanger their safety and impacts their education —and the education of their peers too.
“If a child has been exposed to a Covid-19 positive individual, they should not attend school, even if they are feeling well.
“In the pandemic, any individual’s risk has a significant impact on their community.”
The school was approached for comment.
