Here are a couple of Tatiana's letters (taken from Divniy Svet - a book about Empress Alexandra):
1916
Christmas
My priceless, dear Mama.
I pray that God helps you now in this awful, difficult time. May He bless and protect you from all evil. I believe the soul of our beloved Friend is always with us and that he prays for you, my sweet angel Mama.
With affectionate kisses from your loving daughter,
Tatiana.
New Year 1917
My sweetest Mama,
I hope the Lord God blesses this New Year and that it will be a happier one than last year. And that, perhaps, there will be peace and an end to this nightmarish war. And I hope, my dear, that you will feel better yourself.
1000 kisses my precious angel from your loving and faithful daughter,
Tatiana.