"Children are left dealing with all these tough feelings they can't express," Briar said.
"It can be very isolating for them.
"We want to help normalise their feelings, so they don't feel alone."
At Briar's group, young participants will be encouraged to articulate their feelings through artistic exercises, and through narrative therapy, which helps externalise emotions by making them into a "character" that has moved into their life.
"For example, we get people to see anger as something they deal with, rather than themselves as angry.
"It separates the problem from the person."
Briar said the most common emotions for children whose parents have separated are anger, confusion, and "a lot of sadness underneath it all".
As children don't understand the mechanics of an adult relationships, they tend to turn the blame on themselves.
"It's how they make sense of it -- they think, 'Mum and Dad aren't together because I didn't eat all my dinner, or I wasn't kind to my brother.'"
She said these children can struggle at school and feel stressed by moving between "the different worlds" of their new homes.
Some children Briar has worked with have had a parent abandon the family altogether.
"That's not uncommon.
"When that happens, it's important to focus on strength-building -- helping the kids see the positives in their life story."
Briar works predominantly with young children experiencing grief and trauma, which she finds extremely rewarding.
"It takes a lot of gentleness for kids to open up -- but, once you build that rapport, you see changes happen."
The children's support group will run every Friday for six weeks from July 31, with sessions running from 8.15am to 9.15am. Sessions are free, with breakfast provided. For more information, call 06 3700 5716.
