Another foster shepherd, I picked her up today-she'd been at the local shelter TOO LONG. Tyler named her Cher (because we have Sunni!???)
So Sunni had to be dominant to her...note the raised tail, and the new (BIGGER) girl is being submissive...size matters not!
No I don't think they are related - Sunni's got an entirely different build and their heads are different. Cher has either Collie (Rough) or GSD in her...and even though she's twice as big as Sunni...she rolls over!
The only true wisdom is in knowing you know nothing.