Maureen Greaves, a Church Army lay preacher, received the honour in recognition of her services to the community in north Sheffield.
She said: "I couldn't believe the work I do would warrant such an honour."
Alan Greaves was attacked in 2012 as he walked to his church in Sheffield, dying a few days later.
Despite her loss Mrs Greaves said she had been determined to keep her up the charity work among the community.
"Being involved in a murder and a trial, it was good to come back to work, it took my mind off it."
Mrs Greaves said: I have a strong Christian faith and that enabled me to do it."
She and her husband set up a food bank for families with limited income in the garage of the couple's home.
They then took over a shop to improve distribution to those most in need just weeks before his death.
Mr Greaves suffered "catastrophic" injuries when he was battered with a pick-axe handle.
The retired social worker was walking to St Saviour's Church to play the organ for the service, something he had done for 40 years, when he was attacked.
The father-of-four died three days later in hospital from serious head injuries.
Jonathan Bowling, 22, was jailed for life after pleading guilty to the murder.
Ashley Foster, 22, of Wesley Road, High Green was sentenced to nine years for manslaughter after a jury cleared him of murder.

The stamps will feature characters such as Darth Vader, Luke Skywalker and Yoda and will also feature three scenes from the new film, Star Wars: Episode VII - The Force Awakens.
They will go on sale on 20 October.
The widow of a church organist beaten to death on Christmas Eve has been appointed MBE in the Queen's Birthday Honours list.
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Eighteen new first class stamps are being released by the Royal Mail to celebrate the Star Wars movies.