Won't you be my neighbor?

I was in my house with my sister, and we had locked down the house and turned off all lights because of a zombie virus sweeping our neighborhood. We watched an infected neighbor entered her own house where we knew her two girls would be, but it was too great a risk for us to open up our own house and enter the other to try to help them. Suddenly the two girls ran out into their yard, and I threw open our door and yelled for them to come inside. As they headed our way, their zombie mom came running after them, and she was catching up. I slammed the door shut after the girls ran through and held it closed while yelling for my sister (standing right next to me) to lock the door. She turned the lock, and I let the door go only to see it start to fall open. I again threw all of my weight and strength against the door as the zombie started pushing on it, and I watched in horror to see that our door wouldn't lock.