I am trying to making blinking eyes using switch layers and I am running into a problem. Please help

1. I created 3 pictures ( EYE FULLY OPEN, EYE 1/2 way closed , EYE FULLY CLOSED), I guess we could call the images A, B and C respectively for ease.
2. I put the 3 vector images in a SWITCH layer called BLINK
3. Then I go to the timeline
4. Go to frame 1 and I make A the active child
5. Go to frame 5 and make B the active child
6. Go to frame 8 and make C the active child.
7. I play the animation from the start and only my LAST active child shows (i.e. C)
I swear I saw someone do the same exact thing in thus video below (58 seconds into it)
https://www.youtube.com/watch?v=XzOkiU9jJi8
I am applying the same concept except with eyes. Why is his one changing on the time line and mines isn't. After I make something the active child do I need to PRESS something after?
Thanks again.