Dear Mr. Avery,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located Lists of Incoming Passengers, 1917-1938 in the Records of the Office of the Quartermaster General (Record Group 92) that includes an incoming listing of the USAT Cedric with Della Amo (instead of Delia Amo). The records are not yet digitized and available in the Catalog. For access to and/or copies, please contact the National Archives at College Park - Textual Reference (RDT2) via email at email@example.com.
We also searched Ancestry and located a Della Amo listed on the WWI transport record for her son Norbert Brannan. There may be a fee for using Ancestry. Instead, you may view these records online at one of NARA's facilities for free via a NARA PC. For the nearest NARA location, please consult our web page at https://www.archives.gov/locations/. Also, some of the images from Ancestry are available for free on Family Search at https://www.familysearch.org/en/.
We hope this is helpful. Best of luck with your family research!