Friends of a San Francisco mother who was struck and killed by a stray bullet Tuesday set up a crowd-funding account to help pay for her funeral expenses. Maria Lourdes Soza, 32, was hit in the head as gunfire erupted from two vehicles speeding by her home in the city’s Bayview after she had picked up her three children from school. When she was hit, her other children, ages 9 and 13, began crying while her boyfriend ran to her aid and called for help. On Wednesday, her sisters and 13-year-old daughter, Brianna, gathered at a memorial of flowers and candles in front of the home at Revere Avenue and Ingalls Street. An SUV that may have been involved in the shooting, though, pulled up to the Old Calm House restaurant on the 200 block of Bayshore Boulevard minutes after the killing. Soza’s friends and family said they would truly appreciate any help given, adding that “she was a loving sister, daughter, wife, mother and friend.”