If there was a court ordered placement it would have taken place through the Orphan's Court of Lehigh County PA. Records for this court are available online only through 1915, so you would have to contact the court to determine where the records for the time period you are interested in are. They may still be at the courthouse or in an archive.
Dear Ms. Kosmatka,
Thank you for posting your request on History Hub!
In addition to the advice from the previous poster, we suggest that you contact the Pennsylvania State Archives to obtain a list of Allentown orphanages from 1927 to 1939. You may then contact the institution to request a record search, or search any records from the orphanage that may be held by the Archives.
You also may wish to contact KidsPeace, which was the The Children’s Home of Bethlehem and Allentown in 1926, and according to their records, “shifted focus from orphanage to foster care services, to deal with growing numbers of children in need during the Great Depression”. They may have archival records or be able to direct you to the information you seek.
We hope this is helpful. Best of luck with your family research!