Note the will of John Baxter father of Hannah Baxter where it is clear that in 1717/8 Hannah Baxter is both "Hannah Moss, widow" and mother of Benjamin, John, Thomas, Hannah (now Carver), Mehitable and Sarah Dyer. This makes it perfectly clear she was married first to Joseph Dyer and second to Joseph Morse:
"To my grand children & three daus. of my dau. Hannah Moss £20 more out of it, equally at wifes deceas"
"to my grand children Benjamin, John, & Thomas Dyer & they to pay their 3 sisters, to Hannah Carver £30, Mehitable Dyer £20, Sarah Dyer £20"
"Daughter Hannah Moss, widow, to have use of £100 before willed my grand children, her children, in case she want it."
Note the other Dyar children of Hannah Baxter predeceased her. And daughter Elizabeth Dyer is named explicitly as the daughter of Joseph Dyer's first wife in his will.
The marriage date of 1683 given by Mary Loving Holman in Stevens-Miiler 2:23 is clearly derived from the date of the first recorded child Hannah Dyer identified in the will of John Baxter. This indicates the demarcation between the children of his first wife and the children of his second wife.
Note below in the will of her father in 1719 she was named Hannah Moss (Hannah Morse). She would have been a widow of her second husband at this time.
[435R] Lieut. JOHN2 BAXTER (Gregory1) Baxter born Dec. 1 1639 at Roxbury; died Apr. 29 1719 ae. 81, or Apr. 20 1719 ae. 80 (GS), Hancock Cem. Married Nov. 24 1659, Anna (or Hannah) White, born ____ at Weymouth, died Feb. 29 1723/4 (record of Joseph3 Baxter), dau. of Thomas & (_____) White of Weymouth. He lived in a house now standing at N.E. corner of Spear & Camel Sts., built about 1650 by his father, and the oldest house now standing in Quincy. He was elected selectman 1693, 1696, 1701, 15, commissioner 1694, fenceviewer 1699, moderator 1697, 8, 1702, 4, 5, 6, 7, 15, on committee to seat the meeting house 1697, on the committee of Purchase Lands 1699 etc., Representative 1701-4, constable 1705. He was in King Philip's War 1675 (Reg. 37:28). Children of Lt. John & Anna born at Braintree (Quincy):
i . Hanna, May 6 1660; m 1st about 1683, Dea. Joseph Dyer of Weymouth as
2nd wife. married 2nd int. Apr. 18 1713 at Weymouth Capt. Joseph Moss or Morse of
Sherborn. She was a widow in 1718. Capt. Joseph3 Morse (Joseph2, Samuel1), died 1717
at Sherborn. She died Sept. 4 1727 in 67th year.
ii . John, Oct. 28 1663; died May 28 1666.
+ iii. John, Feb. 14 1666/7.
iv. Thomas, Apr. 27 1670; died Jan.7 1692/3.
+ v. Samuel, near 1672.
+ vi. Joseph, June 4 1676, bapt. June 11.
[435] 21:404 Will of John Baxter Mar. 24 1717/8 – June 4 1719: To wife Hannah lower room of newest end of my dwelling house & 1/2 my cellar during life & all money & moveables except £60 & one feather bed & furniture for son Joseph & £20 more for him at decease of my wife. To my grand children & three daus. of my dau. Hannah Moss £20 more out of it, equally at wifes decease, & remainder between my 4 children. To eldest son John my now dwelling house & barn & all upland, salt & fresh meadow adjoining & half my lands in fence field, next to land of John Ruggles & 1/2 upland bot of Joseph Parmenter & John Sanders that half next his own land & 1 ae. salt meadow & 1/2 my three lots of purchase land in the 600 acres. To son Samuel besides already given, 4 ae. salt meadow in Broad Meadows adjoining his own & 1 ae. salt adj. the town's land & Wm. Savel's & rest of land in fenced field & other half of upland at Pumpkin Hill, next to John Ruggles next to said hill & my right in town swamp joining the town's land, between John Beal & Wm. Savel & other half my 3 lots in 600 ae., he paying £160 to my grand children Benjamin, John, & Thomas Dyer & they to pay their 3 sisters, to Hannah Carver £30, Mehitable Dyer £20, Sarah Dyer £20. To sons John & Samuel my lot at Ancients Ordinary & rest of my purchase lands, Samuel's half in Fenced Field to include 7 ae. already given. Daughter Hannah Moss, widow, to have use of £100 before willed my grand children, her children, in case she want it. Sons John & Samuel executors. Witnesses: John Hinds, Peter Newcomb Jr., Joseph Parmenter.