Travel after passing the citizenship test

[ffl3883]

Hello,

My wife passed her citizenship test and interview in Dec 2018. She is scheduled to have oath ceremony on Jan 23rd. She went out of USA for 3 weeks and came back to the country on Jan 15th. Mainly visiting family and friend. On N-445, There is a questions about "Since your interview , have you traveled outside the United State". She answered yes. What document does she need to bring to support her answer ? Is there anything needed to be careful ?

Thanks

Regards

ffl3883

[pmf123]

They never asked me for proof, just the dates and reason for travel. I went out of the country 3 times between my interview and oath.