There can't be two sentences in a sentence. Your sentence has two independent clauses connected by a comma and a coordinating conjunction.
"She didn't ask for help, so she had to do it all by herself."
Is it a sentence made up of two clauses?
Otherwise, are they two sentences coordinated with a conjunction 'so'?
I'm pretty much confused. Please help me out teachers.
Remember that an independent clause is a phrase that can stand alone as a sentence.
You can tell that it's two independent clauses because each clause has its own subject and verb.