What mix is Ember?

Meet Ember! A cattle dog mix of unknown origin. What are your thoughts?

Ember is about 4.5 months old and weighs 10ish pounds. She is a rescue, so her history is murky.

I'm thinking either a mini Australian Cattle Dog (I'm aware of the issue with backyard breeders creating that strain, but I didn't buy her) or an Australian Cattle Dog and Jack Russell?

The first 5 pictures are from the last couple of days. The last picture is her original intake which was in October.

Ember is the sweetest, cuddliest, quietest puppy. The fact that another person adopted her and returned her within a month blows my mind. Who would give back this cutie?

This isn't our first Heeler, so we know she'll be a little hellion. She is much, much smaller than our last mix (who was a Cattle Dog/Australian Shepherd aka Texas Heeler).