Rhea is married to Nikhil, who is the brother of either Amrita or Karan since she is Karan's sister-in-law on his father's side. Given that Amrita and Karan are siblings, and Nikhil is married to Rhea, Rhea is Amrita's brother's wife, which makes her Amrita's sister-in-law and therefore Rhea is also Jasbir's sister-in-law by marriage. 

Ranveer is the son of Jasbir and Amrita, while Kavya is the daughter of Rhea and Nikhil. As Rhea is the sister-in-law of Amrita, her daughter Kavya would be Ranveer's first cousin, as their parents Amrita and Nikhil are siblings.
In a family, Jasbir is married to Amrita, and they have one son, Ranveer. Amrita's brother, Karan, is married to Isha, and they have a daughter, Simran. Karan's sister-in-law on his father's side, Rhea, is married to Nikhil, and they have a son named Yuvraj and a daughter named Kavya. How is Rhea related to Amrita, and what is Ranveer's relationship to Kavya?
Respond very briefly.