Is any of the following techniques preferred over the other? If so can you tell my why? Please.

Hannah grabbed the coins, "they're mine," she shouted.

Hannah grabbed the coins, "They're mine," she shouted.

Thanks
Michael

Punnaburra, the convention for punctuating dialogue is that the quoted words always start with a capital letter, whether what precedes it is just a speech tag, or full stop. So these two are correct:

She shouted, "They're mine."

Hannah grabbed the coins. "They're mine," she shouted.

Hannah grabbed the coins and shouted, "They're mine."

Hannah grabbed the coins, shouting, "They're mine," and waving her sword.

These are not correct, because 'Hannah grabbed the coins' and '"They're mine," she shouted" are grammatically separate sentences, which must be separated by a full stop.

Hannah grabbed the coins, "They're mine," she shouted.
Hannah grabbed the coins, "they're mine," she shouted.
Hannah grabbed the coins. "they're mine," she shouted.

Hope that helps.

Thanks Emma. I raised the query because I see both examples used in published work.
Michael