fmfmods:

BUFF FEMSHEP MOD (Source Files for manual install)
One .mod file to give Femshep a more defined body. Six meshes have been altered: Alliance officer dress blues, crewman uniform, science uniform, underwear, dress*, and injured. This affects 3 different PCC files (CTH, SHP, NKD), so remember to back them up. If you use intro outfit replacement mods, this can be installed over without conflict. A separate source package with each UPK has also been uploaded for advanced users who want to manually install the meshes. Detailed instructions in the readme. Requires ME3 Explorer.

*This does not alter any DLC files, so to ensure the appropriate model shows up in any forced dress scenes in the Citadel DLC, you must edit your Coalesced (instructions here). Unfortunately, this does not make the default dress textures any less hideous.
**Because the mesh is shared with NPCs, all female crew will also have this body type. The same goes for dress blues and science, but the changes are subtle and mostly make the arms less tube-like.