Seven generations separate Ashlee Nelson from William Hatch but the little girl is proud of her link to a man who was sent to Australia for stealing sheep.

The eight-year-old was among about 80 people presented with a Descendants Day Ceremony certificate at Fremantle Prison this week. The yearly event recognises convicts, pensioner guards and warders who arrived in WA from 1850 and their contribution to developing the Swan River Colony.

Ashlee said she had researched William's arrival on convict ship Minden with her gran's help.

"The convicts were important because they built a lot of roads and special buildings, like Fremantle Prison," she said.

Angus Bottrill, 89, who received certificates for his great-grandfathers - one a guard and the other a prisoner - researched his convict ancestor's legal case.

"I was getting to that age where I was interested in my ancestors, so I went to England to find where they came from and I studied them," Mr Bottrill said. Genealogist Gillian O'Mara, who has tracked family members since the first Descendants Day Ceremony 23 years ago, said people were no longer ashamed of their convict ancestors.

"We've had three premiers from convict descent - Brand, Gallop and the current Premier," Mrs O'Mara said.

Heritage Minister Albert Jacob said he was proud of his convict heritage and the event helped people understand that the convict era was an important part of WA's history.