Take a look at the original sentence again:
As Irene scooped stuffing out of the Thanksgiving turkey, she saw gold glinting
from the breadcrumbs, finally, she had found
her earring, which she had lost early that morning.
You wanted to fix it this way:
As Irene scooped stuffing out of the Thanksgiving turkey, she saw gold glinting
from the breadcrumbs finally, she had found
her earring, which she had lost early that morning.
To delete the comma between breadcrumbs and finally would cause an equally bad problem, a fused sentence. A fused sentence occurs when you have two main clauses joined with no punctuation whatsoever. She saw gold glinting from the breadcrumbs is the first main clause. Finally, she had found her earring is the second main clause. The spot between breadcrumbs and finally needs a stronger break than blank space.
You might want to consult the rules for fixing comma splices and fused sentences.
Go back to the sentence to try again.