A true Buddhist does not pay attention to Feng Shui. As long as the mind is quiet and has the blessing and protection of Buddhas, there will be Feng Shui treasures everywhere.
If your colleague is really a disciple of Buddhism, he should offer salvation to his classmate’s miscarried child, take refuge for him, teach the unborn child not to hinder his mother again, and practice chanting Buddha’s name well. Strive to be reborn in the West as soon as possible and be introduced to the Pure Land of Buddhism. Chant sutras and recite Buddha's name for this child to help him pass away. You can choose to recite the Ksitigarbha Sutra and the Rebirth Mantra several times and dedicate them to your children. You also need to recite the Buddha's name and dedicate it to your children more often. Mainly the Ksitigarbha Sutra, but you can also choose other classics such as the Amitabha Sutra, the Heart Sutra, and the Great Compassion Mantra. As long as the intention is sincere and pure, the child will surely be guided by the compassion of Buddha and be reborn in the West