Studying cold brown dwarfs (BD) is key to understanding the diverse characteristics of Jupiter-like atmospheres. Coconuts-2, a wide binary system composed of a T9 BD and an M3 star, presents a unique opportunity to study these cool objects. As part of a JWST program to study the coldest BDs, we obtained NIRSPEC G395H high resolution spectra and MIR F1000W, F1280W, and F1800W photometry for the T9 component. In this work, we performed a detailed analysis of the age of the system by studying the membership of the M3 star to moving groups. We found that the system is relatively young (414 Myr). We confirmed this age by measuring rotation periods and metallicity of the stars in the group. With this new information, we estimated precise parameters for the T9 BD. In this talk, we will present our age analysis, the resulting parameters for the BD, the atmospheric composition obtained from the JWST spectra, and discuss the apparent discrepancy between the derived age and the T9 component's photometric colors, which suggest it might be older. This comparison will help us interpret BD characteristics in the context of their atmospheric and evolutionary states.