N-400 Selective Service and Mother's alien number

[MacDonne]

I am filing for N-400. I'm 39 and I have been a green card holder since September 1999. Do I still need the Selective Service SIL (Status of Information Letter)? From what I understand I do not need one anymore, correct me if I am wrong. My mother became a US citizen in 2005. In the application, it is asking about my mother's Alien number. Unfortunately, when my mother passed away her belongings was moved around. We can't find her passport or even certificate of citizenship. How can I resolve this issue? Thanks in advance.

[newacct]

Well, did you register for Selective Service? You still need to answer the question about whether you registered. But even if you didn't register, you don't need a status letter since you are 31 or over.