We performed variational calculations of the s-shell hypernuclei 4 Λ H, 4 Λ He and the p-shell hypernucleus 7 Λ Li within a recently developed Fermionic Molecular Dynamics code. The YNG potentials considered in this work give substantially different Λ separation energies. Comparison of the Λ spectra of the mirror hypernuclei 4 Λ H and 4 Λ He reveals very small and mostly opposite charge symmetry breaking effect in contrast to experimental data, which indicates that more sophisticated interactions are required. In 7 Λ Li, the Λ hyperon pulls the α and d clusters in the 6 Li closer together, which confirms the "glue-like" role of Λ.