There is no doubt in my mind you will keep Lily safe.
Our little Missy is so loud she scares our fox. She is about 15 lbs.We still watch her carefully when she is in the dog run. Usually Charle is with her when they are in the 5ft. fenced in area. Chunky Butt Charle would never be bothered. He is 35 lbs. He would probably play with the fox, where Missy is an attack schnauzer. Yappy like all of them.