get oath waiver- US naturalization last step for mother

[Viji20202020]

I am a naturalized US Citizen.  My mother got a green card in 2003.  She started getting dementia in 2012  I sponsored  US Naturalization for mother in 2019.  she failed the first oral interview - since N648 was considered inadequate.

The USCIS Officer at Dallas, TX suggested we get revised N648 from licensed physician  to get waiver for civics and English test  and  also separate letter for oath waiver.  I submitted all the documents  including proof that I am biological daughter. The  second interview her N648 was accepted and her waiver for testing accepted. Now to approve oath waiver,  they sent letter seeking physician letter, guardinaship letter, tax returns.

I submitted physician letter, Tax returns, my citizenship and medical power of attorney after 1st interview.  I have all documents except guardianship.  This will take 4-5 months and lots of expense.  On reading

https://www.uscis.gov/policy-manual/volume-12-part-j-chapter-3  i find i can seek to get oath waiver.  What do you suggest?

Edited August 14, 2020 by Viji20202020
Location added