If she's been paid directly from DFAS, then 1099-R's would have been issued to her.
If she downloads her 1099-R(s) from the website I cited in my previous post, she'll see the mailing address they've been using. If the address they have is wrong, you can correct it on the DFAS website.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
