Well, the difference between killed and modified live vaccines are; a "live" vaccine is made from a live virus or bacteria that has been weakened. This causes the body to make protective antibodies, but does not usually cause the infection. Live vaccines generally provide long lasting protection in one dose. Killed vaccines are made from a virus or bacteria which has been killed, these types of vaccines generally require multiple doses and annual boosters to boost immunity. So, they both protect from the disease or infection without causing the actual disease or infection, but with the Live vaccine, there is a slight chance of developing the actual disease or infection. So, your cat is pretty safe since she was given the killed vaccine. Hope this helped!
Myself, Vet Tech