"Missing rings don't mean the end of relationships," she wrote on Twitter. "Blessed to be with my beautiful family."
Panettiere, 26, and Klitschko, 40, began dating in 2009 but split in 2011. They reconciled two years later in early 2013, he popped the question that October and they welcomed Kaya in December of the following year.
In May, Panettiere announced she was seeking holistic help for her continued struggles with postpartum depression.
The postpartum depression I have been experiencing has impacted every aspect of my life," she announced on Twitter at the time. "Rather than stay stuck due to unhealthy coping mechanisms I have chosen to take time to reflect holistically on my health and life."
It was recently announced that the actress would be returning to Nashville for season 5 when it moves to CMT.