Aguilera, her hubby Jordan Bratman, her mother-in-law and sister-in-law were spotted at the store picking out items for the baby registry for two hours.
A store's employee said that Aguilera seemed very excited about the baby and also told them the gender of her baby, but asked to keep it private.
"She looked beautiful. She had a little bump. She said she was so excited to have a baby," People quoted store sales employee Crysta Smith, as saying about the singer.
The couple, with the help of the relatives bought baby shower, including blankets, diaper bags, bottles and clothing.
"They registered for all the accessories. They were both picking out things together," Smith said.