According to conservation group Ishaqbini Hirola Community Conservancy, the bodies of the two animals were found in Garissa, eastern Kenya.
White or otherwise, all reticulated giraffes (Giraffa reticulata, the species found in the conservancy and throughout northern Kenya) are considered endangered by the International Union for Conservation of Nature.
The white appearance of the giraffe is due to leucism, a genetic condition that causes skin cells to have no pigmentation.
Two white giraffes are shown in the Ishaqbini Conservancy in October 2019. Fuzz Dyer Northern Rangelands Trust
The Kenyan Wildlife Service is investigating the killings.
As poachers target giraffes' meat and skin, the species' population as a whole has declined by 40% in the past 30 years. A third white giraffe was reportedly born in 2019.
"Also, the white giraffe was a big boost to tourism in the area", Mr Ahmednoor added. The motives of the poachers was unclear. The female and her calf were part of a family of three white giraffes.
In 2017, the news of the presence of the white giraffe in Kenya made headlines across the world, with various people marvelling at its sight. Unlike albino animals, those with leucism have dark eyes.
The latest killing highlighted the threats facing the animals, including poaching for their meat and hide, along with the loss of their habitat because of infrastructure development and land clearing for agriculture and firewood.