One of the "Silver Dagger" family of songs which includes the Carter Family's "Who's That Knocking at My Window". Cecil Sharp's #57C has nearly identical lyrics to this song. The melody is very close to that of "Silver Dagger" in this section.
Steve Roud observes on one version of the song titled "O! Molly Dear Go Ask Your Mother":
"A whole book could be written on this song and its connections with other songs which involve young men at their sweethearts' windows at night, disapproving parents and silver daggers. Hugely popular with North American traditional singers, 'Drowsy Sleeper' was also collected regularly in Britain and appeared on broadsides there from at least the 1820s".
Recording history:
    1926 – Kelly Harrell – "O! Molly Dear Go Ask Your Mother"
    1927 – B. F. Shelton – "Oh Molly Dear"
    1938 – Blue Sky Boys – "Katie Dear"
    1938 – The Carter Family – "Who's The Knockin' On My Window"
    1956 – The Louvin Brothers - "Silver Dagger" on Tragic Songs of Life
    1960 – Joan Baez's - "Silver Dagger" on her debut album
    1963 – The Country Gentlemen - "Silver Dagger" on Hootenanny: A Bluegrass Special
    1964 – Ian & Sylvia – "Katie Dear" on Four Strong Winds
    1964 – Bob Dylan – "Silver Dagger" appears on The Bootleg Series Vol. 6
    1964 – Dave Van Ronk - "Silver Dagger" on Inside Dave Van Ronk
    1999 – Dolly Parton - "Silver Dagger" on The Grass Is Blue