Wow, she's beautiful! She seems to look well fed and well kept, do you think perhaps somebody is looking for her?
Will you be able to see if she's microchipped and have her scanned at the vets? She seems far to special to be wandering about with nobody caring for her, and if her mum had a collar then at least somebody partially cares for her/them?
Perhaps you should see about finding thier owners first before you get attached? Not that I do'nt want you to have her! But just in case it ends up hurting you in the long run?