She was one of the Park's 26 female rangers and was highly committed, showing true bravery in her work.
The men were gorilla trekking at Virunga National Park on the eastern border when their convoy was ambushed by armed militants.
Britain's overseas secretary says that two British vacationers being held hostage in Congo have been launched two days after being kidnapped.
"I pay tribute to the help of the DRC authorities and Congolese Insitute of Nature Conservation", he added.
Five Virunga rangers and a staff driver were killed just last month during an ambush in the central sector of the park.More news: Microsoft Extends PC Games To Its Digital Gifting Program
It was the deadliest attack in recent years and took the total number of rangers killed to 175.
"We want to convey our deepest condolences to her family and our honest gratitude for her courage in the service of Congo".
Congolese authorities are working with the Foreign Office to repatriate the British tourists, according to a park statement.
A spokesperson for the Congolese Institute for Nature Conservation (ICCN) said: "For the moment the [ICCN] can not communicate much about the incident because the hostages are still in captivity".
In April, Mr de Merode, told the BBC World Service that recent attacks were part of "a bigger picture which involves the trafficking of natural resources".More news: Mercedes' Lewis Hamiton tops second practice at Barcelona
In peacetime, the Virunga National Park has barely fended off the local warlords and gangsters seeking to strip it off its valuable timber or the government officials and vested corporate interests seeking to exploit its oil.
The park, which is a Unesco world heritage site, is home to critically-endangered mountain gorillas, lions, elephants and hippos.
Their park guard was killed and their driver was also kidnapped.
The Foreign Office now - and before the kidnapping - advises against travelling to the area.More news: Ireland's first day of Test cricket starts and ends with a bang