moving her could have caused a delay, Id actually let her go back into the main tank, to avoid stressing her even more. If you have enough cover (plants are good), and a not-way overstocked tank, most of the fry will live. I dont think she would die from not birthing the remaining fry, Im pretty sure they would just reabsorb... But then, Ive never had swordtails, so that may be way off.