The "Do It Well" singer, who delivered son Max and daughter Emme on February 22, was thrilled when Mark presented her with the stunning eight-carat yellow canary diamond ring.

A source close to the singer said: "Jennifer wasn't expecting such a generous gift, but Marc wanted to give her something to remember the day by."

Meanwhile, Jennifer - who is believed to have spent a staggering $1.4 million on giving birth in a luxurious birthing suite at Long Island's North Shore University Hospital - has hired exclusive Los Angeles baby boutique Petit Tresor to design a nursery in the couple's Puerto Rican estate.

The 38-year-old star, who reportedly received $6 million for the first photo shoot with her babies, recently employed a masseuse and color therapist for the newborn twins.

Jennifer is also said to have ordered two Shetland ponies for Max and Emme, along with diamond-encrusted rattles, 600 thread count Egyptian cotton for the baby's cots and designer babygros for the nursery wing in her Los Angeles home.

The "Wedding Planner" actress recently revealed becoming a mother is the best thing that has ever happened to her.

She said: "Your heart is connected to them. With all the things that Marc and I have accomplished in our lives, this is the biggest thing that will ever be."