I do not have the answer to your question. However, I did find your family on FamilySearch.org. I "cleaned-up" some obvious discrepancies and posted some hints which might help you. The site is free. Your ancestor is GQSR-5LF. Good luck.
Dear Ms. Roberts,
Thank you for posting your request on History Hub!
We suggest that you check with Wisconsin Department of Health Services - Vital Records Services for a record of amending her birth certificate or perhaps an adoption by Paul Steffen. Perhaps her parents had to provide a birth certificate when Vivian attended school. Unfortunately, the requirements for school enrollment, voting driver’s license, a marriage license, or applying to Social Security were not as legalistic as they are now.
We searched the National Archives Catalog and located the Population Schedules for the 1930 Census (T626) in the Records of the Bureau of the Census (Record Group 29), which indicates in the schedule for Washington County, Wisconsin that Evelyn was employed as a hired girl at a private residence. Most of the schedules have not been digitized yet and available using the Catalog. For access to the non-digitized schedules (T626), please contact the National Archives at Washington, DC - Textual Reference (RDT1) via email at firstname.lastname@example.org.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT1. We apologize for this inconvenience and appreciate your understanding and patience.
The 1930 Census (T626) has been digitized by Ancestry. In response to the COVID-19 pandemic, the National Archives has partnered with Ancestry to make the vast majority of their NARA-digitized holdings freely available to the public. Anyone with Internet access may create an account, access NARA records, and use other Ancestry resources, such as their educational offerings and family tree-maker application. For more information see Ancestry’s announcement -- “Free At-Home Education Resources From Ancestry® and Access to Nearly 500M National Archives Records”.
We hope that this is helpful. Best of luck with your family research!