present perfect a present perfect continuous

Witam!
Zastanawiałem się jaka jest różnica między czasem Present Perfect a Present Perfect Continuous, mianowicie chodzi mi o zdania:
"She's been playing the violin since she was 3" i "She has played the violin since she was 3".
Proszę o wyjaśnienie, które jest poprawne, a jeśli oba to jaka jest różnica.

Both are perfect, as it were.

"She's been playing the violin since she was 3" draws your attention to the activity.
She must have been practicing for years.

"She has played the violin since she was 3" gives prominence to the result.
May I call it acquirement? She must have devoted years to the sport.

Think about it.