Louis Lavater's 12 Preludes are likely Romantic-era miniatures, offering accessible explorations of melody and harmony. These pieces are often charming and expressive, suitable for developing pianists.
Focus on producing a beautiful tone and maintaining a consistent melodic line.
12 Preludes is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 5.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 12 Preludes lasts about 15 minutes.
12 Preludes is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.