Pierce gave his step daughter away on June 14 at a small ceremony with Bella her daughter acting as bridesmaid.
A source told the Irish Sun: “Bella looked beautiful and wore a wreath of flowers around her head that matched her mum’s.
“It wasn’t a day to be sad. Alex and Pierce were both smiling broadly.”
Charlotte’s mother and grandmother both died of the disease.
Her daughter Bella wrote a moving message for her mother on Facebook,
“I love you mummy!! I really, really do.
“You’re such a special person and you’re my angel.”
In a brief statement announcing the death of his daughter Brosnan said: “On June 28th my darling daughter Charlotte Emily passed on to eternal life, having succumbed to ovarian cancer. She was surrounded by her husband Alex, children Isabella and Lucas and brothers Christopher and Sean.
“Charlotte fought her cancer with grace and humanity, courage and dignity. Our hearts are heavy with the loss of our beautiful dear girl.
“We pray for her and that the cure for this wretched disease will be close at hand soon. We thank everyone for their heartfelt condolences.
Staff at the 60-year-old actor's local church in Malibu, California, have paid tribute to his daughter and promised they'll put on a special service in her memory.
Sister Mary Prendergast, of Our Lady of Malibu Church, explained: "We are very sad to hear about Mr. Brosnan's daughter passing and he is in all our thoughts and prayers.
"Mr. Brosnan has attended the church for some years and his children have attended our school. Today we will put Charlotte's name in the prayer book and when he returns to America we will be here to offer him support and be able to plan a mass in Charlotte's honour, should he desire us to do so."
Pierce - who is devastated following Charlotte's passing - has thrown himself back into work as he tries to cope, jetting from London back to Belgrade, Serbia, to resume filming his new movie 'November Man' on Tuesday.
He adopted Charlotte and her brother Christopher, the children of Pierce's first wife Cassandra, following the death of their father Dermot Harris in 1986.
He and Cassandra went on to have a son Sean in 1983 before her death, also from ovarian cancer, in late 1991.
Pierce has since married Keely Shaye Smith and the couple have two children, Dylan, 16 and Paris, 12.