“ Matilda the Musical ” star Alisha Weir is set to lead upcoming coming of age feature “Underdogs,” the debut film from writer and director Fabia Martin (“The Rev”). The adventure comedy follows two teenage girls, Nel and Zadie, as they run away from foster care only to find themselves competing at the world-famous pedigree dog show Crufts. The girls form an unlikely bond while meeting a cast of wacky characters across the West Country as they search for freedom and family. “Quirky dog-enthusiast Nel is eager to win over her new foster sister, but when an incident pushes Zadie to flee in search of her estranged birth mother, the pair find themselves on the run to Birmingham in a stolen ambulance,” reads the synopsis.…