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The presence of evolved stars in high-redshift galaxies can place valuableindirect constraints on the onset of star formation in the Universe. Thus weuse a combination of PEARLS GTO and public NIRCam photometric data to searchfor Balmer break candidate galaxies at $7 < z < 12$. We find that our Balmerbreak candidates at $z \sim 10.5$ tend to be older (115 Myr), have lowerinferred [O III] + H$\beta$ emission line equivalent widths (120 \r{A}), havelower specific star formation rates (6 Gyr$^{-1}$) and redder UV slopes ($\beta= -1.8$) than our control sample of galaxies. However, these trends all becomeless strong at $z \sim 8$, where the F444W filter now probes the strongrest-frame optical emission lines, thus providing additional constraints on thecurrent star formation activity of these galaxies. These weaker trends likelyreflect the bursty nature of these Epoch of Reionisation galaxies, which canlead to a disconnect between their current star formation activity and SEDprofiles, and their more extended star formation history. We discuss how strongemission lines, the cumulative effect of weak emission lines, dusty continuaand AGN can all contribute to the photometric excess seen in the rest-frameoptical, thus mimicking the signature of a Balmer break. Additional medium-bandimaging will thus be essential to more robustly identify Balmer break galaxies.However, the Balmer break alone cannot serve as a definitive proxy for thestellar age of galaxies, being complexly dependent on the star formationhistory. Ultimately, deep NIRSpec continuum spectroscopy and MIRI imaging willprovide the strongest indirect constraints on the formation era of the firstgalaxies in the Universe, thereby revealing when cosmic dawn breaks.

EPOCHS IX. When cosmic dawn breaks: Evidence for evolved stellar populations in $7 < z < 12$ galaxies from PEARLS GTO and public NIRCam imaging