It sure didn't take Thomas long to remarry - Harriet died in June 1888 and he married Mandy/Amanda by Halloween. Guess he was having trouble handling 5 kids, including a newborn, on his own.
I show him and Harriet as having at least 5 kids - Jane, Amanda, Mary, Henry & Emma. He then had 6 more with Mandy. (I have a niece named Mandy/Amanda, likely named after this woman). My kids are descendants of one of those 6 kids, George Washington Morrow.
All can be viewed on my website www.donersincanada.tribalpages.com so if you find you need the access code, just send me a message from the website or to email@example.com as I don't want to post the passw0rd on this public forum.
The 1901 census has daughter Emma as 12 years old, and she is a daughter of Harriet, so I have since revised my birth year for her to 1888 (from 1889) since you say Harriet was dead by June of 1888.
After Thomas's death (bet. 1904 & 1921 sometime), Mandy married Albert Zalahan in Havelock, Ont. in 1921. - no kids.
One thing odd is that I show daughter Amanda as a child of Harriet, not Mandy/Amanda. Coincidence?