06/08/2012 at 05:55 AM EDT
Leaving beau Garrett Hedlund
behind, Kirsten Dunst recently headed to Mexico, where she planned a special getaway for her best friend, Molly, who's getting married.
Dunst, the bride-to-be and four bridesmaids all stayed at the St. Regis Punta Mita Resort, where they kicked off the bachelorette party in a festive way, sipping margaritas while donning sombreros.
"Kirsten booked a three-night stay in the Presidential suite," a source tells PEOPLE. "She hosted a champagne ritual in Molly's honor on the first night of their stay."
The second day of the gals' extravaganza was more mellow.
"After morning yoga on the beach, Kirsten and her friends spent the next day laying out by their pool," the source says. "But the highlight was that night, when Kirsten arranged a special sunset BBQ."
For their final day, the ladies relaxed at the spa. "Kirsten took everyone for customized massages," the source says. "That night, the group ventured into town for dinner at local favorite, Si Senor." – Jennifer Garcia