There are 2 deaths of Martha Mather in Bolton 1837 to 1841, but both are infants. Solomon's death record describes his occupation as "Husband of Martha Mather, Hand-Loom Weaver", so it seems she is still alive in 1844. However, she was not with him in 1841.
The burial for 8 March 1832, is for Martha wife of Bold Mather, aged 46, so not this Martha!
In 1841, Martha (75, Ind) may have been living at Castle Hill, Hindley, Wigan with John Grime (26, Farmer) and Elizabeth Thomason (55, Assistant farmer). If this was her, then she died at Hindley in 1852, aged 89.
In 1850, there is a death registered in Salford for Martha Mather, aged 75, buried 3 April 1850 in Manchester Cemetery. This is a good age match, but will be the wife of George Mather. George and Martha Mather (both 65) were living in Pendleton, Salford in 1841.