Assunta,

I don't know if Kim saw your inquiry.  She is the mother we all saw at the
Conferences this summer...... carrying twins in a sling.
Twins are born being accustomed to being crowded up against each other.  Just
put them both in the sling, making sure both are in a position where the nose
is not buried and baby can breathe "new" air  on-going.
Kim is short and had no problem carrying older babies in one sling.  By then,
they were sitting up and peering over the rail of the sling to see where they
were going.  They were very content.
The family should have two slings available for times when two adults are
available for single carrying times..... especially nice if air traveling.
I have worn twins in two slings at one time, but as they got heavier, the two
slings pulled on each other and were choking me.

Opal Horvat, BA, IBCLC
Bergenfield, NJ