What mix could this silly girl be?

This is my foster, affectionately known as Scraggle. I got her from a shelter in CA. She’s 2 years old, ~16-17lbs. Mostly legs with a slender frame and floppy ears. She has a bit of a beard, but it was trimmed because she took exploring the outdoors a little too seriously (see last photo). She has speckled skin and the fur along her spine is the same color as her ears. I keep coming to the conclusion she’s Parson Russell x mini poodle, or something similar. I’m super curious what ideas others have. She loves to stand up and sit with her front paws up. She’s very agile. She has a relatively low prey drive (not so Russell of her).