Will and Jada have NO issue with their 13-year-old Willow Smith pic

13-year-old Willow Smith is old enough to make decisions on who she hangs with -- even innocently in bed ... this according to Willow's parents.
Sources connected to the Smith family said ... Will Smith and Jada Pinkett Smith believe their daughter is "very mature" ... enough so to make her own decisions, as long as they don't clearly cross the line.

Will and Jada view the now-famous photo of Willow in bed with 20-year-old "Hannah Montana" star Moises Arias as innocent fun ... an expression of art.

The Smiths have known Moises for years, and he's best friends with 15-year-old Jaden.