New here.. Can you help me identify my dogs breed?

I recently adopted a rescue dog who is growing like a weed, we have had her 3 weeks, she was at 13 lbs. when we got her, now she is at 20lbs. I was told she was German shepherd which she may be, I'm just curious to what others think? she does look like a shepherd with all of her characteristics except her ears (fuzzy and floppy... any input would be appreciated.. really doesn't matter either way just curious. could she be mixed if so with what?