This is a great question. My first recommendation for you is to talk to your veterinarian. He or she is likely a better informed source than your friend, even if she's had cats all her life, etc. If you don't feel you can talk to your veterinarian about this, then I would consider finding a new veterinarian. I also like to stress that regardless of what vaccines your cat needs, she should still have a yearly physical exam. This exam is just as important as the vaccine as it helps ensure your cat is healthy and can catch disease early.
Vaccinations can be very confusing and the recommendations often change. I try to decide on what vaccinations and how often they are needed based on the cat's age, lifestyle and general health. I also tend to look toward the American Association of Feline Practitioners vaccination guidelines for reference.
Let's talk a little more in detail about the vaccines.
The rabies vaccine is considered a core vaccine and should be done in all cats, indoors and out. How often the rabies vaccine is done can vary dependent on state or local laws, and the type of vaccine used. While it may be unlikely that an indoor cat would come in contact with a rabies carrying animal like a bat, raccoon or skunk, the vaccine protects against this off chance. I have had multiple clients where a bat has gotten in the house and been killed by the cat (if this ever happens do not throw way the bat..minimize your contact with it and call your local health official immediately). Just a couple weeks ago I also had a client whose cat was bitten by a raccoon when it broke in through a screen on her porch and attacked her cat. Rabies is a fatal disease and can not be diagnosed in a live animal. The rabies vaccine is also recommended for your legal protection..in some areas it is the law to vaccinate your cat for rabies. Also to consider, if your cat was to bite someone and they did not handle the situation well, your cat may need to be quarantined for a significant amount of time or they could ask/demand you euthanize your cat to be tested for rabies. I think of the rabies like insurance. Certain rabies vaccines now have very few side effects and most are considered very safe in our cats.
The distemper vaccine is also considered a core vaccine and is done as a series during kittenhood, a single vaccine is given one year later and in general this vaccine is then given every three years. This virus protects against multiple serious viruses your cat can contract. If your cat did not have her distemper vaccine last year, I would suspect your cat is already on a three year protocol for this shot.
The leukemia vaccine is considered a non-core vaccine and is usually recommended for kittens or for adult cats that are at higher risk of the disease, ie..generally outdoor cats that may have contact with other cats. This does not sound like your cat, but your veterinarian can help you determine what is best.
With all this said, I feel vaccines are important but should be chosen carefully for each cat. Side effects and reactions can occur but tend to be infrequent..about 1:100 for systemic effects and even less likely for serious side effects like a mass at the injection site.
Hope this helps. I hope your cat stays in good health as well.