When was the snowball incident?

[EmmyLee]

Tatiana seemed to have bad luck in that area! In Tobolsk, she slid headfirst down a little snow mountain they built and nearly knocked herself out.

Tatiana wrote about that in a letter to her Russian tutor. She certainly had a good, sweet sense of humour, though: "Another time I was going down the hill backwards and banged the back of my head really hard against the ice. I thought nothing would be left of the hill, but it turned out that neither I nor my head burst, and my head didn't even hurt. I've got a hard head, don't I? Eh?"

I'd never heard of this incident before. Thank you, Ferah, for providing the excerpt from the letter. Might I ask where you came upon this letter? I'd like to read more of them.

[Holly]

Tatiana seemed to have bad luck in that area! In Tobolsk, she slid headfirst down a little snow mountain they built and nearly knocked herself out.

Tatiana wrote about that in a letter to her Russian tutor. She certainly had a good, sweet sense of humour, though: "Another time I was going down the hill backwards and banged the back of my head really hard against the ice. I thought nothing would be left of the hill, but it turned out that neither I nor my head burst, and my head didn't even hurt. I've got a hard head, don't I? Eh?"

You can find it on the main Alexander Palace website under 'letters from Tatiana in exile'.
I'd never heard of this incident before. Thank you, Ferah, for providing the excerpt from the letter. Might I ask where you came upon this letter? I'd like to read more of them.

[EmmyLee]

Thanks, Holly.

[Lalee]

I think the children were outside the palace playing in the snow. I do not know if Anastasia was annoyed with Tatiana or if it was a harsh prank she played, but she rolled a rock inside the snowball and it hit Tatiana directly in the face. I don't know if Tatiana went unconscious, but it was definitely a big shock and she fell on the floor stunned. Anastasia hardly ever cried but, realising that she had possibly come very close to harming her sister, she completely burst out into tears. I don't know if any adults were with them or what happened after that.

Perhaps Holly could help!

Yes, it was in Poland and everyone was outside and the children were playing in the snow and Anastasia got the idea to get a rock and put some snow around it and she then threw it at Tatiana which hit her in the face very hard, knocking her to the ground. Realizing exactly what she had done, it scared her and she cried. I don't think she really understood how much that would hurt her sister before she did it and thought it would be a clever thing to do. 

Thank you, Holly! I knew you would be able to help!

Yes, you can read them on the AP here or at Livadia.org in Tanya's Diary.

[Marie-Antoinette]

I could be wrong, but I think it was 1912.
On a site of Anna Vyrubova's memoirs, the chapter it
Is mentioned in deals with a lot from 1912:

http://www.alexanderpalace.org/russiancourt2006/vi.html

If you press ctrl then f when you have this link open and then type in 'snow' it goes straight to the quote.

I'm guessing Anna Vyrubova was with the girls at the time seeing as she remembers it and she wrote it in her memoires.