I strongly believe that we have the amazing ability to forge an energetic links as a specie (race).We also have those strong emotions towards each other ,which allows us to be too close or too distant.To all of us ,at certain point, has happened to think of somebody and after some time this person would contact us in some way.There is not a reason for me to assume that this linkage is destroyed after we have passed.Even if we did not reincarnate around same people the connection is still there.However ,some indeed reincarnate in same family either the entire family or few members of it might meet together after many years and lives.
Denise Linn has reported same observations during her past life regression work with clients in her book "Past Lives,Present Miracles".
There is another famous and well documented case about the death and rebirth of the twins Jillian and Jenifer Pollock ,within the same family.
Leading investigators on the field are Raymond A. Moody M.D,Ian Stevenson,William Bernett MD.Denise Linn and Barbara Meiklehohn-Free work with clients on this field and give us feedback in their books.It will be beneficial to you to get to know about the work on field Broken345 ,does not matter if you pick the more psychological or more spiritual/occult aspect to it.
I do believe that every person we encounter in our life is significant in some way.This person can be significant even if he/she has negative impact on our welfare ,because we always learn in one or another way.Some of those people we might have called through this past life linkage ,and some we might have called through new one formed as we went on with our mundane life.
There is not simple answer to so fundamental questions,but what one can do is to devote his/hers time to read about the research done on them so far.
I would like to add that in Tibetan Book of the dead is mentioned that we choose our parents in the moment of our conception.Many people believe that we choose when and where we are reborn ,if we think within the lines of this information, we probably will choose to be reborn around familiar people(soul-wise) ,rather than strangers.