When you read:
ἑορτὴν ποιοῦσιν (they make=organize a festival), think of all those festivals seen in films, on TV, in real life. Then you can realistically say (or think): Wow, what a
ἑορτή.
They certainly
καλὴν ἑορτὴν ποιοῦσιν in ...(wherever it may be).
Use your imagination, your memories of times past, things seen, felt, smelt, touched, thought, admired, hated....! For all words and structures, not just for festivals!
At last, women are introduced and all things feminine. About time, too, after all 50% of the world are women. And since women are beautiful, strong, energetic ... in a way different from men, let's express that difference the Greek way in article (the) and adjective endings as well.