Nikki Bella isn't just a former WWE Superstar ... she's a super-mom too -- spending some quality time with her four-year-old Matteo after filing for divorce.
The former wrestler stepped out in Napa Valley Friday ... taking her son to his dance class with a big smile on her face.
Check out the pics ... both Nikki and her son look ready to work out -- twinning in all-black, sporty outfits.
Nikki definitely participated in some self-care Friday afternoon .