Having become something of an heirloom, the gown Charlotte will be wearing was made by her grandmother's great-grandmother.

"It was made in England, and it must have come out [to Australia] with my great-grandmother Mary Watson," said Charlotte's grandmother, Maria Stephenson.

"[Mary's] daughter, Francis, she wore it too. She might have been the first to wear it in Australia, because she was born in Ballarat.

"But I think she had sisters too who might have worn it in England."

It is the same gown Charlotte's father, Sam Stephenson, wore at his christening at St Michael's Cathedral in 1981.

The youngest of four brothers, Sam was Mrs Stephenson's only child to wear the gown, because his christening was the only one that did not coincide with another's. 

At the christening of Charlotte's cousin Jeffrey Murphy in 1958, the gown was thought to be just over 100 years old. With time now elapsed and research further conducted, the family are confident it has a much longer vintage.

"We can't work out when [Mary Watson] made it but I'd say it's probably between 170 and 200 years old now," said Mrs Stephenson.

For 47 years after Mrs Stephenson's father's christening, the gown fell out of use.

Now in its fourth generation of use, the gown is approaching retirement.

"There's been nieces, great-nieces, cousins, it's even gone to America and back," said Mrs Stephenson.

"This might be the last time, because it does have a lot of moth holes in it now."

Since the passing of her mother, the gown has come to reside with Mrs Stephenson's sister Denise, who lives near Newcastle. 

In preparation for Saturday's occasion, Mrs Stephenson took custody of the garment and began her work to restore it.

"I gave it a good soak for about five hours and that brought out the stains well," she said.

"There were a few holes in it, it's getting very fragile. I've noticed a couple of tears coming in so you've got to be so careful."

When it can be worn no longer, the still family hopes to preserve it as a constant heirloom. 

"We've been trying to get to everyone who's worn it to get pictures from their christening, then we can put them in a book or something. But who knows how many have had it?"

Following Saturday's event, the gown will return to the care of Mrs Stephenson's sister in Newcastle.