Zilla and Zoe (2016) online

Zoe, age 10, is obsessed with making horror films. A deadline for a big horror contest is coming up, and Zoe is determined to win. But when her father, concerned about her increasingly gory activities, orders her to stop making horror films and shoot her sister's wedding week instead, Zoe has no other choice... To win the contest of her dreams, she will have to turn her sister's wedding into a horror film