Hi Everyone, this thread is old but I hope it's still active !
I am facing the same situation, I applied for the N-600 to get a certificate of citizenship through my mother, the application was accepted and USCIS is asking me to come for an interview and bring proof that my mother was physically present in the USA for 5 years, two of which are after the age 14 and all prior to my date of birth.
My mother was born in 1960 so We don't have any record of her physical presence in the USA at that time, as she moved overseas when she was 3 and moved back 3 years before I was born.
Any help would be appreciated, thank you.