Hey few things... ghost shrimp I beleive require more brackish conditions to actually breed though they do tolerate freshwater fine. Second is with cherries, I have read that ghost shrimp will sometimes kill the babies and eat them... I looked into keeping both in the same tank when I set up my breeder but after reading that I decided deff not worth the risk. Also in a tank that small any potential problems will likely arise due to lack of room. So my opinion is either go take the ghosts out and breed the cherries or make the water conditions more pristine for the ghosts to let them breed either or!