Deenie,
I would think this is your family, found in Rotemansarkivet (on CD), population register of Stockholm 1878-1926.
? Anders Reinhold Fast b. 24 May 1829 in Stockholm (parish unknown). Plater/blacksmith.
D. 12 Apr 1891 in the poorhouse of Katarina parish, Stockholm.
(According to an earlier population register, 1855, Anders Reinhold Fast was born 25 May 1829. At the time he lived with his wife in Katarina p.)
? His wife was Eva Matilda Fast, maiden name Timper, b. 29 Jan 1836 in Katarina parish.
D. 21 Jun 1884 in Maria parish, Stockholm. Cause of death: pulmonary tuberculosis.
Children:
? Gustaf Magnus Reinhold Fast b. 5 Aug 1855 in Katarina p. Factory supervisor.
His wife Emilia Sofia Fast, maiden name Jonsson, b. 9 Aug 1852 in Hedvig parish, Norrköping town.
Their daughter Märta Viola Fast b. 19 May 1901 in Maria p.
In 1926 the family lived in Högalid parish, Stockholm.
On her 27th birthday 19 May 1928 Märta Viola Fast married Kurt Otto Wallin b. 27 Sep 1899 in Adolf Fredrik p., Stockholm.
Märta Viola Wallin d. 28 Jul 1972 in Sankt Göran p., Stockholm.
Kurt Otto Wallin d. 18 Mar 1976 in Sankt Göran p.
(Sources: Swedish population register 1970 and Swedish Death Book 1950-1999, both on CD.)
? Emilia Matilda Wilhelmina Fast b. 10 Oct 1857 in Katarina p.
26 Oct 1879 she married plater Johan Abrahamsson b. 6 Jun 1849 in Hammar parish, Örebro county.
Their daughter Elin Sofia Mathilda Abrahamsson b. 19 Sep 1880 in Maria p.
The family emigrated to North America 30 Aug 1881.
? Adolf Wilhelm Efraim Fast b. 15 May 1863 in Katarina p. Plater trainee. To N. America 21 Mar 1882.
? Anna Maria Fast b. 8 Feb 1866 (parish unknown). To N. America 6 Jun 1883.
? Klara Amanda Charlotta Fast b. 11 Sep 1870 (parish unknown). To N. America 16 Mar 1888.