you have their birthday . . . what do you LOOK for ??
strong conjunctions or 150 degree aspects (with an orb of 1 degree, 2 max)
the more conjunctions and quincunx (150 degree) aspects between your charts, the more "likely" you are "soul mates"
maybe this is good, maybe this is a roto-rooter to your soul
if you have none, but have tight trines or oppositions, there is still the possibility of a strong mutual connection
but they, in my opinion, are not "true" soul mates
also, the orbs need to be TIGHT
the conjunction AND the quincunx are the 2 strongest "markers" of karmic "ties"
they tell the story most clearly; they are the strongest indicators of past life connections
'tis true, 'tis true