Message 1:
Many a day we have spent together, and none of them I regret, only the fact our days are finite weighs me down. Eternity by your side I desire the most. Find the next clue in the room I spent much time in, though you always insist I do not need it.
Message 2:
Another step closer to finding the treasure, my darling. Ever since we started dating, you have every day proven I made the right choice to approach you. I am so happy I decided to go work on my english after the tournament. You can find the next clue where I store what you tell me I do not need, for what is inside is more important.
Message 3:
Rest easy in the knowledge that you found another clue. I must congratulate you on your skills. Know then that the next clue can be found where we shared many a moment teaching each other, and then enjoyed the fruits of our labours.
Message 4:
Read this with a smile, you deserve it, and I love seeing you smile. Only one more clue to go before you find the treasure. You can find it in the room where we both spend less time than we would wish.
Message 5:
Yes, this is the final clue, good job, my love. The treasure you seek is hidden outside the house, where we have store our supplies that make sure we do not freeze in winter. I can only say I enjoy watching you procuring said supplies.
Fleur is telling Harry something more in those messages, of course. 😉