"At first, we thought it would be a max four weeks, and then it kept getting longer and longer," Chrislip told People magazine.
"At this point, we've just accepted that we don't know … but we wouldn't have it any other way. She is so loved and right now, we are the constant in her life."
Chrislip decided to become a surrogate mum after giving birth to her own son Camden in 2018 in the hope of helping someone else become a mum.
She said that she couldn't imagine not being able to have her own biological child, and had been lucky enough to have an easy pregnancy, so looked into the process.
In 2019 she was chosen to be a surrogate for a couple in China with the plan for the couple to be there at the birth.
But after being stranded in China, they asked if Chrislip and her husband could look after their baby instead of it being placed with a nanny agency.
After a lengthy discussion, the couple decided it was the right thing to do.
Now a year on, Chrislip is wary of not growing too attached to the baby girl knowing she'll have to eventually give her up.
"We definitely love her and will always care for her, but we understand she is not ours," she said.
"We just treat her as our own because at this stage in life it is so important to have the proper attention and love."
In exchange for being a surrogate, Chrislip received between US$35,000 (NZ$47,500) and US$40,000 (NZ$55,000) in compensation – which they used to pay off student loans and buy a bigger home.
While she's not sure if she could be a surrogate for another family again, she says she's open to doing it again for the same parents should they want more kids.