Only one source is currently known which mentions Elizabeth Allen in connection with the Ripper murders. She allegedly gave a statement to the police (possibly to Inspector Edmund Reid) involving a suspect "living not far from Buck's Row." Her information apparently tallied with statements given by Mary Ann Connelly and Eliza Cooper.
Inspector Reid, Detective Sergeant Enright, Sergeant Goadby and other officers then worked on a slight clue given them by 'Pearly Poll.' It was not thought much of at the time; but what was gleaned from her and other statements given by Elizabeth Allen and Eliza Cooper of 35 Dorset Street, Spitalfields, certain of the authorities have had cause to suspect a man actually living not far from Buck's Row. At present, however, there is only suspicion against him. 
We don't know what information Elizabeth's statement contained, but it seems likely that it involved the suspect known at that time only as "Leather Apron".
- The Echo, 20th September 1888
- Jack the Ripper: The Facts, Paul Begg (Robson 2006)