Hi Amrita,
There is no problem for a mother of a 5 months old baby to do a supported shoulder stand against the wall; she may find her way back into an unsupported shoulder stand quite rapidly after this although if she is still breastfeeding she must be careful with her lower back for longer than women who are not breastfeeding. It is good to build up the back strength by a progression of easy bridge poses with arms stretched under the lower back and pushing from the hands palms faced down, using full breath. Also it is important to check that new mothers have fully realigned their pelvis, most particularly forward tilt and sacro-iliac asymmetry exacerbated by the pregnancy, before resuming shoulder stands and even more seriously, headstands. Otherwise, the weight of the upper body on the misaligned pelvis might cause backache and weakness in the medium and long term, particularly around the menopause. We need to think of long term well being in postnatal yoga, this is very important in the Birthlight focus on renewing or creating 'core strength' postnatally.
Congratulations in getting your postnatal class going. Have you noticed that there will be a special focus on the Fourth Trimester of Pregnancy at the July Birthlight conference? the idea is to encourage a sound progression in postnatal yoga from birth rather than women returning to their yoga classes without addressing the changes that pregnancy has effected in their bodies.
All best
Francoise.