Jamie Lynn Spends 17th Birthday Shopping, Eating Out

“They both seemed really happy, both in really good moods,” the source tells  People of the couple’s outing near Aldridge’s home in Liberty, Miss. “Jamie Lynn had a big smile on her face.”

Spears, who is pregnant with Aldridge’s child, took in a quiet dinner with Aldridge, 18, at the restaurant.

“It was just the two of them,” says the source. “They were like a little adult couple, very low-key.”

They then went to Wal-Mart, where Spears looked at sleeping bags. Jamie Lynn recently has been flashing a big ring from Aldridge. They are expecting their baby this summer.

Meanwhile in Los Angeles, Jamie Lynn’s big sister Britney Spears gathered with the rest of the Spears clan for a family dinner in Los Angeles.

Britney, parents Lynne and Jamie and brother Bryan joined a group of about 10 people for an Italian feast at Ristorante Peppone in Brentwood.

She (Britney) was in a great mood, and had dinner with her family and friends,” a restaurant source says.