Please explain :

My own, real sister called me up yesterday telling me about new excitedly and
we decided that we would go shopping as soon as she comes back to town.

real sister is subject of verb called past tense.
real sister is also subject of telling . Why not used past tense of tell is told, why use telling?

new is adjective why it stands before adverb excitedly?

Where did you find such an awful, badly mangled sentence?

"My own, real sister called me up telephoned/rang me telling to tell me WHAT? excitedly, and we decided that we would go shopping as soon as she comes back to town".

Also, what do you mean by "my own, real sister"? Do you have a sister who is not real? Or a real sister who is not your own?

PaulM