  Thanks to its exceptional near-infrared photometry, JWST can effectively
contribute to the discovery, characterization, and understanding of multiple
stellar populations in globular clusters, especially at low masses where the
Hubble Space Telescope (HST) faces limitations. This paper continues the
efforts of the JWST GO-1979 program in exploring the faintest members of the
globular cluster NGC 6397. Here we show that the combination of HST and JWST
data allows us to identify two groups of MS stars (MSa, the first-generation,
and MSb, the second-generation group). We measured the ratio between the two
groups and combined it with measurements from the literature focused on more
central fields and more massive stars compared to our study. We find that the
MSa and MSb stars are present in a $\approx$30-70 ratio regardless of the
distance from the centre of the cluster and the mass of the stars used so far.
