I fixed it..
Here you go: "I offer you [this picture] for you to remember [this moment] and I hope that you will keep the original picture [this one].
The winter of your wedding ceremony."
To: "[My - probabily, can be the sister of somebody else, though. Unprecise expression] Sister and Nahun [i'm not sure. Could be a nickname. Very strange word. Might be "Nașul" - "to the godfather", if your grandmother had a very specific way of writing the letters].
And finally: "Damle" could signify a shortened form of "Damele" ("the ladies) or it could be a nickname or it could be, in fact, "Domle" which is an informal and oral version of "Sir!" in the vocative case (such as in: "Hey, sir!"). Moreover, "domle" is a way of expressing a very large variety of feelings, situation in which we say "Oh, sir! How good were those times" or similar ones.
Hope you'll find this useful.
PS: Due to the fact that the text isn't very precise and that the words themselves present some doubts, I've added th explanation between the brackets. I cannot offer you an undebatable translation...