Bonnie is a modest salon piece composed in the mid-19th century American tradition. It employs basic harmonic structures to highlight a simple, nostalgic melody.
The main technical hurdle is keeping the Alberti bass accompaniment quiet and steady beneath the melody.
Comparable difficulty and character — good candidates for what to learn next.
Bonnie is rated Henle level 2 of 9 — beginner repertoire, roughly ABRSM grades 2–3. In the RCM system it corresponds to about level 2.
You should be comfortable at Henle level 2 — meaning you can already play level 1–2 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of Bonnie lasts about 2 minutes.
Bonnie is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Believe Me, If All those Endearing Young Charms by Irish Folk Music, "s'kommt ein Vogel geflogen" by Siegfried Ochs, Au Hameau (In the Hamlet) by Franz Behr — see the full similar-pieces list on this page.