It will take me some time to collect data on all the names listed above.
George's will left 12 pence to all of his of his children, and it appears that all of his mentions in the will for his five "least" children (children of George and Katherine). This includes William, Matthew, Henry and Samuel, but his last son (Gideon) was not mentioned. William and Matthew traveled with George and Katherine in 1635, and were old enough to stay in Sandwich after George died. Katherine's three youngest children moved to Boston when Katherine married John Collins. The deed from "Henerey and Samuell Allin of Boston" to George Alline of Sandwidge, land in Sandwich given by father George Allin dec'd, deed with consent "of our mother to say now Kathren Collins who hath interest therin during her life," deed witnessed by John Collins, shows that Henry and Samuel were in Boston then. Gideon, Katherine's last son, was the administrator to the probate of John Collins, so lived in Boston with Katherine and John Collins. Henry and Gideon both settled in Milford CT. I think that Samuel moved to the next town, Fairfield CT, and sold two lots in 1663, but there is no record to tie Samuel of Boston and Samuel of Fairfield so this is only a suggestion.
George's children by his first unknown wife are more difficult. As The Great Migration (Immigrants to New England 1634-1635, V. 1, A-B, p. 30) says, "At one time or another just every Allen male in southeastern New England has been placed as a son of George Allen." Five children of George can be proved by contemporary records: Ralph (Sr.), John, Robert, George and Rose.
The Great Migration also mentions two other possible children of George: Francis and James. Francis is generally listed as son of George because he lived in Sandwich, but there are no records that prove that Francis was a son of George. On the other hand, Francis is mentioned with Jedediah Allen son of Ralph Allen Jr. in several records, although no records state that they were related. The Society of Friends records show that Francis was poor, and supported by the Society a few times, and he mistreated his wife. Most of these records mention Jedediah Allen, with or without other Allens, so I would suggest that Francis was related to Ralph Allen Jr. and his son Jedediah Allen. A list of land in 1667 also appears to show that Francis lived near Jedediah.
A James Allen lived in Sandwich between 1663-1667. The New England Marriages Prior to 1700 lists James as "James Allen (1636-1714) & Elizabeth [Partridge] (1644-1722); b 1663; Braintree/Sandwich/Chilmark." Waldo Chamberlain Sprague (1983, Genealogies of the families of Braintree, Massachusetts, 1640-1850, including the modern towns of Randolph and Holbrook and the city of Quincy. New England Historic Genealogical Society & Quincy Historical Society, Boston, 1983) states that this James Allen was a son of Samuel Allen of Braintree MA, and he removed to Chilmark by 1671 when he had a son Ebenezer Allen. He died in Chilmark in 1714. George Allen Jr. also had a son James, but he was born on 5 Aug 1658 so too late for the other James Allen.
Hester Allen was born is Sandwich, the record showing Hester Allen was born the 8th of December 1648, but there is no other mention of her. Since Ralph Allen Jr. married Hester or Esther Swift, I think that the Hester Allen born in 1648 was a daughter of Ralph Allen Jr.
Thomas Allen was of Barnstable MA, and brother of Matthew Allyn of New Haven CT.
Caleb Allen (b. 1646) and Judah Allen (b. 1651) were both sons of George (Jr.) & Hannah Allen, so grandsons of George Allen (Sr.).
Finally, Thurcaston, Leicestershire, England Allen records are commonly cited, but I haven't seen any clear records that relate them to George who arrived in Boston in 1635. The Parish Registers of Thurcaston show several Ralph Allens, and at least one George Allen, but none of the records match Ralph and George of Massachusetts: some Thurcaston records
Raph Allyn & Ann Nuberry mar 5 May [1622]
[chr. of Raph son of Raph Allyn bapt. 19 Dec [1622]]
Raph son of Raph Allyn bapt. 19 Jan 1622[/3]
Mary dau. of Raph Allyn bapt.1 Aug 1624
Danniell son of Raph Alline bapt. 28 May 1625
George son of Raph Allen bapt. 4 Oct 1628
Mildred dau. of Raph Allen bapt. 9 Jun 1630
Raphe Allyn & Jane his wife mar. Mar [1634]
Jane wife of Raph Allen the elder of Crapston butcher buried 16 Jan 1653[/4]
Raph Allen the elder buried 3 Aug 1661
There are NO marriage of a marriage of a George Allen and Katherine in the Thurcaston parish registers. I checked!!
So, what I put in this text is relatively quick, but might answer some of the questions from the prior discussion. Let me know if you need more details.