Stream winner reborn as human If someone enters the stream and becomes a sotapanna (stream winner), then he would have at most, seven lifetimes left. What the stream is, is defined in this answer as:


  This noble eightfold path — right view, right resolve, right speech,
  right action, right livelihood, right effort, right mindfulness, right
  concentration — is the stream. (SN 55.5)


Thanissaro Bhikku further comments here that:


  The coming-together of these factors is called the stream because it
  leads inevitably to two things, just as the current of a tributary
  will lead inevitably to a major river and then to the sea. In the
  immediate present, the stream leads directly to the arising of the
  Dhamma eye, the vision that actually constitutes this first awakening.
  Over time, the stream ensures that — in no more than seven lifetimes —
  one will be totally unbound.


The Dhamma eye is explained as the ability to see firsthand and experientially, the impermanence of the five aggregates and dependent origination.

My questions are (for rebirths as a human):


How does a reborn stream-winner know that he or she is one?
Does being a stream-winner in a previous lifetime, mean that one would be reborn into a devout Buddhist family in this lifetime or would definitely be led to the Dhamma eventually?
Is the reborn stream-winner's Dhamma eye open immediately at birth, or only after he or she encounters the Dhamma and returns back to the Noble Eightfold Path?
How is it guaranteed that the reborn stream-winner would not choose another path or another teacher, and drop out of the stream, considering that we do not remember previous lifetimes?
Please provide any info from the canon regarding this.
How does a reborn stream-winner know that he or she is one?
  


Like a math or music prodigy who can easily recall their skillset through just some basic exposure to music or math, a stream-winner would be like that, if not much quicker or even instantaneous since Path/Fruit are supra-mundane skills, unlike mundane fields like math/music.
There're concrete metrics to determine a stream-winner. Details are available in many suttas like AN 9.12, AN 3.87, SN 12.41, etc. (ref: suttacentral.net)


  
  Does being a stream-winner in a previous lifetime, mean that one would be reborn into a devout Buddhist family in this lifetime or would definitely be led to the Dhamma eventually?
  


S/he's to be born into any place(devas or humans) and time where the conditions are conducive to guarantee enlightenment at most 7 more life times.


  
  Is the reborn stream-winner's Dhamma eye open immediately at birth, or only after he or she encounters the Dhamma and returns back to the Noble Eightfold Path?
  


The DhammaEye opens just once and will stay there when the noble disciple makes the breakthrough to StreamEntry, as said in AN 3.94:


  "Bhikkhus, just as, in the autumn, when the sky is clear and cloudless, the sun, ascending in the sky, dispels all darkness from space as it shines and beams and radiates, so too, when the dust-free, stainless Dhamma-eye arises in the noble disciple, then, together with the arising of vision, the noble disciple abandons three fetters: personal-existence view, doubt, and wrong grasp of behavior and observances"


.


  
  How is it guaranteed that the reborn stream-winner would not choose another path or another teacher, and drop out of the stream, considering that we do not remember previous lifetimes?
  


S/he won't switch path since they possess the Seven Great Reviewing Knowledges of Stream Entry (MN 48), one of which is: "Knowledge that no other recluse or brahmin outside the Buddha's Dispensation possessed of a view that one possess." Also see the child prodigy analogy mention in question 1.


  
  Please provide any info from the canon regarding this
  


All refs. should be available on accesstoinsight.org or suttacentral.net