Maud Kells, who was awarded an OBE in the 2015 New Year honours list was at her home near the small town of Mulita when she was attacked.
WEC International, the charity for which she worked, said she was shot twice and wounded in the shoulder and has since been flown by Mission Aviation Fellowship to a hospital in Nyunkunde.
She's now reported to be stable, speaking and recognises people.
The 75-year-old from Cookstown, Northern Ireland, has been involved in the training of Congolese nurses in 5 hospitals and 30 health centres. She has seen a number of armed uprisings. In 2004, returning to DRC after evacuation she helped rebuild battle-scarred buildings.
Douglas Craig, the Scottish Coordinator for WEC International and a good friend of Maud's, told Premier: "Basically she's a woman of faith, and trusting in the Lord to keep her safe.
"She's there not for the good of her health - literally - but for the good of the people, and her heart is really to serve the people in the name of the Lord.
"She was involved in quite a dangerous situation before, so she's been through these situations before and lived to tell the tale.
"When she recovers from this, she won't let this deter her if I know Maud.
"But obviously she'll have to be realistic as to how long it will take to recover."
According to WEC International, when Maud was informed that she was to receive the OBE (for services to people in the Democratic Republic of Congo) she was in DRC, living as she has for much of her life - in the rainforest.
Ulster Unionist Assembly Member for Mid-Ulster Sandra Overend said: "Only a few days ago we heard the news that Maud is to be awarded a great honour from Her Majesty the Queen and now today, this terrible news that she has been shot doing her work in the Congo is shocking.
"I am sure that I share this sadness with so many people from Cookstown and across Mid-Ulster.
"Those that know Maud will hope that her usual determination will provide her with strength to recover from this terrible incident."
WEC director in Ireland Norman Cuthbert said: "Maud is a very, very strong lady. She has a very strong faith, I am sure Maud will recover, although it has been a very frightening experience for her."