  Searches for gravitational-wave counterparts have been going in earnest since
GW170817 and the discovery of AT2017gfo. Since then, the lack of detection of
other optical counterparts connected to binary neutron star or black hole -
neutron star candidates has highlighted the need for a better discrimination
criterion to support this effort. At the moment, the low-latency
gravitational-wave alerts contain preliminary information about the binary
properties and, hence, on whether a detected binary might have an
electromagnetic counterpart. The current alert method is a classifier that
estimates the probability that there is a debris disc outside the black hole
created during the merger as well as the probability of a signal being a binary
neutron star, a black hole - neutron star, a binary black hole or of
terrestrial origin. In this work, we expand upon this approach to predict both
the ejecta properties and provide contours of potential lightcurves for these
events in order to improve follow-up observation strategy. The various sources
of uncertainty are discussed, and we conclude that our ignorance about the
ejecta composition and the insufficient constraint of the binary parameters, by
the low-latency pipelines, represent the main limitations. To validate the
method, we test our approach on real events from the second and third Advanced
LIGO-Virgo observing runs.
