Direct speech inside another direct speech [duplicate]

Solution 1:

Yes, your quote-within-a-quote is almost correctly punctuated.

• Most style books have the final period inside all quotes, so it would end with Everything will be OK.'" (Note: this is for American English and is the method cited in Chicago Manual of Style, 13th ed.)
• he was talking to her has its own subject, he. You would need to precede it with a semi-colon or a full stop. Or you would make drop the he. (Note: @Janusbahsjacquet calls the and a coordinating conjunction and thinks that it is fine as is.)

All in all:

"He was five and a half meters from her. He was talking to her, softly. He told her: 'Please, try to calm yourself down. Everything will be OK.'"