Since no one else clarified the parental information in the past four years and more, I should note that what you evidently have -- with John Alexander's mother being listed as "John" Alexander -- is a corruption of an original statement that a researcher had no name for the wife of John Alexander Sr., so she was entered as "MRS. John Alexander."
In another post made elsewhere on this forum today, I have questioned the assumption that George Alexander (brother of John Alexander Jr.) was born in 1629 in Stirling, Scotland.I believe that it's much more probably that he was born around 1620, and thus age 24 at the time of his 1644 marriage.
If I am correct, the assumed dates for John & George's parents could still be about right.
One item on which I do not at all agree with what you presented is the idea that John Alexander Jr. was born about "1622 in Deerfield, Nouvelle, Angleterre." There were no white people at all in Deerfield, New England (meaning Massachusetts) in 1622.Indeed, there were only a handful of white people anywhere in New England at that early date -- mainly in Plymouth.(Why your source chose to refer to New England by a French transation of the name is beyond me.)
Thus, it's much more plausible that John and his siblings were born in Scotland, prior to the family's emigration to America.