Singer-turned-fashion designer Jessica Simpson, who turned 35 last week, celebrated her birthday by treating her family and a number of friends to a two-week vacation in St. Barts where she showed off her impressive jet-skiing skills.

Simpson chartered a private jet to take around 20 family and friends to the island on July 6, reports usmagazine.com.

According to a source, Simpson and her friends were so excited when they arrived at the island.

"When they got off the plane, the girls were all dancing and skipping around, ready to party. They were holding hands and so excited to have arrived in a beautiful destination,` the source said.

`They rented a boat a few of the days so they could go snorkeling and cruising around the bay," the source added.

On her actual birthday, July 10, Simpson and the guests celebrated it with a Native American-themed party.

`Everyone wore giant feather headdresses and painted their faces. They partied all night long and slept for most of the day. Even when they got up, Eric and a bunch of her friends were still wearing their costumes. They definitely had a lot of fun and didn't want it to end,` the source said.