Hello dear grandmother
I'm good,how are you? Horosho.Mne study really want to come to you and pomoch.U can not come, I will soon be shkola.No kanikuly.Napishi me an answer please. I'll wait Regards Your granddaughter (your grandson)
(your grandson) - внук
Your granddaughter-внучка ( я просто не знаю мальчик или девочка ты)