I would most often express myself as:
"Come to think of it..." but I guess could, on occasion, use "coming"
Coming is the correct spelling.
Are your children coming home? is grammatically correct.
I can think of many correct re-phrasings of "Is she came" If she came Is she lame Is she tame After that, it gets more complicated ... Did she come Is she coming Will she come
Coming
This afternoon you are coming to the Laboratory.
No. r is spelled are and the word order should be: When are you coming?
Yes, "She's coming with us" is correct grammar. It is a shortened form of "She is coming with us."
2012
No, the correct phrase is "he knew winter was coming." The word "had" is unnecessary in this sentence.
"You are going there" is correct if the speaker is not at the location being referred to. "You are coming there" is correct if the speaker is already at the location being referred to.
It appears that both of your options are exactly the same, so either (or both!) are correct.
coming..