On Saturday, she spent the day with her children, Sam, 3, and Charlie, 1½ celebrating Saint Lucia's Day with about 300 other mostly Swedish people at the First United Methodist Church in Boca Raton, Fla.
"Elin and the children were dancing around the Christmas tree with other families and having such a wonderful time," a source tells PEOPLE. "Elin had a look of contentment on her face."
The Swedes gather for this annual fete, usually on Dec. 13, to celebrate the Winter Solstice. Saint Lucia's is also a day to toast family, women and a festival of lights in honor of the Swedish Saint of Light.
Nordergren, 30, and her kids feasted on open-faced sandwiches, Swedish meatballs and sweet treats like ginger snap biscuits, prepared especially for this fun-filled day devoted to family.
"Some of the children dressed in costumes, but Sam and Charlie were decked out in regular clothes," the source tells PEOPLE. "They watched the other children, including one 5-year-old girl who played the violin."
The event began in the morning and lasted till about 6 p.m. Nordegren and the kids stayed for most of the day.
"To watch Elin and the kids and the many other Swedish families come together for this special day was inspirational and rewarding," the source observes. "The room was filled with love."