I think you need to have Orangutango take a look at this thread. Your pup looks a lot like Tango and her brothers and sisters (particularly Winter -- maybe she'll post a pic of him/her for you, I have them in a PM but I don't want to post without permission ).

Tango is a Border Collie/Toller ... and I definetly think your pup has Border Collie in her. I don't really think Sheltie or ACD but it'll be easier to tell once she's grown up.