Mom's managers write sweet letter to kids when she returns from maternity leave

For working moms, the transition back to the office after maternity leaves is one of the hardest parts of motherhood.

But one mom's managers went out of their way to make it just a little bit easier on her.

After Emma Corless' 10-month maternity leave, Kate Dunton and James Rosenwax, her managers at the global infrastructure company AECOM, wrote a letter to her kids.

"We are so lucky to have your mummy returning to work," it read in part. "We've missed her and her brains. She's an amazing mother, but she's also amazing to us! She's a key mentor of our team."

Corless, who has been working for the Melbourne, Australia, company for the last six years, told "Good Morning America" the letter to her sons -- Finn, 2 and Leo, 10 months -- and her wife, Celeste, arrived at the end of her first week back.

"I was feeling exhausted and overwhelmed," she said. "It felt like such a big week for me and my family, and it was so heartening just to know that they were conscious of that."

On her 10-month leave, Corless said she had "fundamentally changed as a person." She said she was anxious for week before her return, worried about how her son Leo would cope in daycare.

"When I received the letter in the post I cried. My partner did, too," Corless said.

In the letter, her managers also wrote, "We promise to look after her."

While on her leave, Corless told "GMA," she was also promoted and able to ease back into work with a three-day work week.

"Without that support and flexibility, I wouldn't have been able to take the job," she said.