The Waratah West couple's five-year-old son is named Hartley Jake. Mr Roberts is the fifth generation of men in his family whose middle name is Hartley and his brother's name is Jake. Their two-year-old daughter's name is Billie Eva.

"It's more of a gender neutral name," Mrs Roberts said about Billie.

"I'm not really a girly girl myself so the names like Florence and all those beautiful girl names are just not my thing, I suppose."

She said the "strong" name suited her daughter "100 per cent".

"She's very confident and she knows what she wants - and she screams a lot," she said. "It's perfect to a tee, she suits that name."

Mrs Roberts said she was surprised to see Billie in second place on the Registry of Births, Deaths and Marriages list of the top 10 baby names in the Newcastle local government area's five most populated suburbs last year.

IN THE NEWS:

The name wasn't in the state's top 10, which was led by Charlotte and Oliver, followed by Amelia and Noah, Olivia and Leo, Isla and William, Mia and Theodore, Ava and Jack, Ella and Henry, Matilda and Luca, Sienna and Thomas and Chloe and Charlie.

The registry will publish the full NSW top 100 in April. Its data shows Billie was the state's 53^rd most popular girls name in 2021.

Billie wasn't the only name that appeared in Newcastle's top 10, but not the state's.

The local leaderboard is topped by Ruby and Oliver, followed by Billie and Thomas, Amelia and William, Olive and Leo, Harper and Theodore, Hazel and Noah, Olivia and Arthur, Mia and Henry, Florence and Hudson and Georgia and Finn.

Meanwhile, the state's most popular girls name, Charlotte, doesn't appear in Newcastle's top 10.

The registry's top 10 names for the combined Newcastle, Lake Macquarie and Hunter Valley areas has Isla and Oliver as most popular, followed by Willow and Hudson, Charlotte and Leo, Mia and Noah, Harper and Theodore, Ella and Elijah, Ruby and Thomas, Amelia and William, Evie and Charlie and Grace and Luca.

Mrs Roberts said she'd received "one or two comments" linking her daughter's name to musician Billie Eilish.

"I can see how people make that connection but it wasn't my intention," she said.

"I know the top names that have been around the last couple of years like Ava, Evie, Eva, Charlotte, they've dominated the list ... so maybe people are just looking for a different alternative?"

Mrs Roberts said Eva was her grandmother Jean's mother's name. She was three months pregnant with Hartley when her grandmother died.

"We always had it in our mind we would name our first Eva if it was a girl," she said.

"He was a boy, but we always had that conversation with my Pop if we have a girl we want to name her Eva. Then things changed and I really fell in love with the name Billie, but still wanted to put Eva in the name."

Sharleen Carroll said she hadn't expected her one-year-old son's name, Theodore, to be so in favour.

"I'm glad I stuck with it, I don't know if I would have picked it if I knew it was so popular at the time, but I don't regret calling him Theodore, he definitely suits it," she said.

It was one of the three boys' names she and her partner Axcel Maverick both wrote on their individual lists of favourites.

"We still hadn't fully decided until he was born and then thought 'Yep his name is definitely Theodore' when we saw him," she said.

"I like to call my son little bear instead of teddy, I feel like it will age well with calling him bear as he gets older. There are so many abbreviations for it, Theo, bear, teddy, he can kind of choose his own nickname."

Theodore's middle name is Edward, which he shares with the other first-born sons in his dad's family.