Vanessa Svebakk, whose daughter Sharidyn was shot dead when the killer mounted his terror attack on the island of Utøya, is campaigning against the memorial proposed to the site, claiming she has not been consulted.
"I'm sitting here with tears in my eyes. Finally, we are being taken seriously," she told NRK after the call on Wednesday. "That a Prime Minister calls and says that one of her ministries will follow the call up is amazing. I do not know if these things happen in other countries."
Svebakk wrote to the Prime Minister on Monday demanding a new, more inclusive process on selecting the site and design for the memorial.
She has now been invited to a meeting on Friday with the ministers of culture and local government to discuss the memorial.
Svebakk launched an attack on the memorial in the middle of last month, complaining that families of the deceased had not been adequately consulted.
"No one should be allowed to make money on our daughter's death, and we would rather not have her name on a memorial," she told Norway's NRK television channel.
On Thursday she told NRK that she was willing to have a memorial, but wanted more influence.
"We want a memorial to honour those we lost and those who survived Utøya," she said. "After this phone call, we finally feel that we are being taken seriously. It is very gratifying."
Svein Bjørkås, who heads Koro, the public art body which selected the monument, has argued that the bereaved were included, with the head of the main support group sitting on the committee which selected the memorial.
The design selected for Utøya, Memory Wound by the Swedish conceptual artist Jonas Dahlberg, has been controversial, with neighbours setting up a campaign group to stop it being built, and one geologist claiming that the rock is too soft for the design to work.
Breivik killed 77 people on July 22nd, 2011, when he detonated a bomb under government buildings in central Oslo, killing eight people, and then drove to a Labour Party youth camp on the island of Utøya, where he opened fire, killing 69.
He is now in jail serving a 21-year sentence.