Thanks everyone!

Popcorn, T-bird doesn't really mind Samantha because all they do is stare at each other as you can see in the photo I posted above.

Miss Meow, the gerbils fit in the palm of your hand.
Here is a photo of Chocolate in her ball next to Samantha when they first met in November.

I hope that gives you an idea of how big they are next to Samantha.
It is funny when both gerbils are rolling around the kitchen in their balls because they will bump into each other sometimes.
Chocolate is better at turning and stopping but sometimes they will bounce off of each other.