QUOTE(irena.t @ Jun 19 2008, 01:22 PM)

Hello, can somebody tell me how long I will wait from sendin N-600 for my dauther, to reseivin letter for her naturalization?
A nitpick. An N-600 has nothing to do with naturalization, and if you sent in an N-600, there will never be a letter regarding naturalization from it. With the N-600, there's no civics exam, no English exam, no oath ceremony, no certificate of naturalization. The person will never be a naturalized citizen.
An N-600 is an application for certificate of citizenship for someone who is already a US citizen before filing the N-600. It's just asking the USCIS to give a piece of paper which verifies the US citizenship that existed all along. It's used by US Citizens who were citizens from birth, or who became citizens by virtue of their parents' obtaining US citizenship (along with meeting some other requirements).
If the processing time seems like it will be too long, remember that anybody who is eligible to file an N-600 is also eligible to file directly for a US passport with the passport agency. It might be faster to let the department of state's passport agency adjudicate your citizenship than to apply for a certificate of citizenship through the USCIS.