It seems your wife is a US citizen to sponsor you green card. If so and she has filed I-130 already, you do not need to provide her US citizenship certificate. But if the I-130 and I-485 will be filed concurrently, she needs to provide the citizenship certificate.
x我看了皮匠老師的博客說不接受私人支票,現在還是這樣嗎?
-私人支票 is fine in your case.
謝謝!八老師和皮匠老師!