I follow the guidelines suggested by the American Association of Feline
Practitioners:
http://www.aafponline.org/resources/guidelines/vaccine.pdf

Even a strictly indoor cat can get diseases that are outside in many
different
ways. Firstly from you, you walk all over the place picking bacteria and
viruses up on your shoes and bring them home. You interact with people and
they have cats or dogs thus bacteria or viruses come off them and shed into
the environment, you being part of that environment. The very air you breath
and catch colds from is the same air your cat shares with the world. Since
your cat is not a kitten she will need a FeLv test (Feline Leukemia) is done
before the shots are given to make sure she doesn't have the disease.

She will need all the shots recommended by the vet and two weeks later a
booster and then she will be good for a year. She is not a kitten so she dos
not needs all those other shots every few weeks, that is for kittens to
build their immune systems.

Any questions?
Gina