She definitely looks like some sort of herding breed. She doesn't look too dissimilar to my Aussie boys when they were that tiny! Her ears are exactly how theirs were. Tiny little triangles.
She does have a tail yes?
So Aussie/Border Collie, something along those lines. She's got an awful lot of white on her, so hearing and eye tests might be a good idea. Herding breeds are renowned for their hip problems so get those checked too.
Did your friend BREED this puppy or buy her or what? It sounds unusual to me that she gave you a dog and she doesn't know its breed. How did she come by her?
And as Kian said, 5 weeks is far too young to be away from her mother. :/