زوجتي العزيزة

زوجتي شخص جيدة،
تطبخ لي عشاء لذيذ كل مساء،
أحبها! :)

It is great, clear and direct... very direct? :) You can enhance it, "شخص" is too "unknown" in Arabic, it is used to address strangers mostly, you can use instead "انسانة" (Human) or "إمرأة" (Woman), which are more gentle and familiar. Using "جيد" is sufficient, but is general and doesn't say much. Instead, you can use a lot of other words:

"مخلصة" -> Sincere
"عطوفة" -> Kind
"محبة" -> Loving
"رائعة" -> Great
"جميلة" -> Beautiful

... etc

I would say:

زوجتي العزيزة
زوجتي إمرأة مخلصة
تطبخ لي عشاء لذيذ كل مساء
!أحبها