Here "they" and "her" refer to the people of Sidon. This can be translated with second person pronouns. Alternate translation: "you will know ... within you ... in you"
When Yahweh says that people will know that he is Yahweh, he is implying that they will know that he is the one true God who has supreme authority and power. See how you translated this in [Ezekiel 6:7](../06/07.md). Alternate translation: "understand that I am Yahweh, the one true God" or "realize that I, Yahweh, have supreme power and authority" (See: [[rc://en/ta/man/jit/figs-explicit]])
The abstract noun "judgments" can be translated using the verb "judge." Alternate translation: "when I judge her" or "when I punish her the way she deserves" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
This can be stated in active form. Alternate translation: "I will show that I am holy when I punish her" (See: [[rc://en/ta/man/jit/figs-activepassive]])