No. If you look the characters, Lakshman is emotional, but Urmila is grounded. She is a balanced girl, but Lakshman can fly off the handle. Same is with Bharat and Mandavi. Bharat is grounded. But Mandavi is impulsive, she can fly off the handle.
Unlike Siya Ram, Lakshman Urmila, Bharat Mandavi has that balancing part in their pairing. What one doesn't have, the other have.
Urmila is like Sita so she is the reflection. Mandavi is like Sita, but not quite like her hence she is the shadow
Same with Bharat and Lakshman. Bharat is like Ram hence reflection. Lakshman is like Ram, but not quite like him hence shadow.