Could she be an ACD?

She was a rescue and was just listed as a mutt. I had a red heeler already (they're best friends haha) and they look similar. She weighs about 20 pounds and the only good photos I have are when she's sleepy, in any other photo you can barely tell theres a dog since it's so blurry from her running around. She is about 2 years old and ridiculously silly and energetic.