Jane Carroll married Henry McCloud but I'm not sure she is yours unless she knocked quite a few years off her age because Henry was so much younger than her. If she is the correct one, the 2 Carroll children are obviously not Thomas's children.
I wouldn't worry too much about the age difference in the death certificate as ages were often not exact.
1891 RG12; Piece: 866; Folio: 102; Page: 7
Henry McCloud 29 Bricklayers Lab Devon Port Hampshire
Jane McCloud 32 Gosport Hampshire
Harry Carrell 5 Lambeth London
Mary Carrell 3 Gosport Hants
Louisa McCloud 6 months Portsmouth
Mary A Robins 69 lodger Portsmouth
However, this family are also in the 1901 census with Jane's age given as 43 and with 5 more children, the youngest Kate aged 6 months. Therefore I dont think this is your Jane as she would have actually been 55 by then and probably wouldn't still be producing a child every 2 years. The only way to prove/disprove it is to get the certificate, unless anyone has access to the Parish records.
Found this site, but can't see them
http://www.knightroots.co.uk/parishes.htm Alverstoke, comes under Gosport.