In August 2014, the Nigerian army bombed Hafsatu's village, then controlled by Boko Haram jihadists.
In her frantic flight along with thousands of others, she could not find three of her seven children.
More than 25,000 people, including some 14,000 children, have been missing since the beginning of the conflict, according to the International Committee of the Red Cross (ICRC).
For Hafsatu whose three children remain missing, a tree planted in their memory offers some solace.
“This tree can be useful to everyone, even when I'm gone, my children will also be able to enjoy it, which helps me feel better,” she says.