Why is one of my dog's ears standing while the other isn't?

Hello, first time dog owner here! Exactly a week ago, we adopted a dog named Daisy. She's two months old. Her mom is an alaskan malamute and her father is unknown (though we think he's a labrador) so she's a mix. Today, we noticed that one of her ears is pointing upwards (just like a malamute's) while the other isn't. This started today.

The first picture is how it used to look like, the second and third is how it looks now. It's impossible to bend it back, because it keeps going back to the original position.

Is this normal? We're thinking of calling the vet in case it's something bad.