To appropriately congratulate your friend, you can translate the given line into English and use that as a basis for your message. The line "Ang pusa ko ay kakapanganak lang nang limang kuting" translates to "My cat is about to give birth to five kittens." So, you can congratulate her on her new brood by saying something like: "Congratulations, my friend! Your cat is on the verge of giving you the most precious gift - a family of five adorable kittens. Wishing you and your feline friend all the best for a safe and healthy delivery."