As a woman, how can I deal with excessive hair like sideburns?

Laser Hair Reduction. Hair reduction per light based technology {i.e. Laser, ipl} is a more permanent solution. As a general rule of thumb, the results of therapy improves as the pigmentation of skin tone decreases and the pigmentation of the hair increases. Another way to put it: fair skin tone and black hair responds the best. Dark skin tone and gray hair will not respond at all. Qualified provider won't burn you.
Hormonal imbalances. Facial hair is a sign of high testosterone levels. Estrogen can be biotransformed into testosterone via the enzyme aromatase. Aromatase enzyme is increased by high Insulin levels. A high carb diet will increase both Insulin (via stimulatlon of pancreas) and estrogen (via competetive inhibition of glucoronidase enzyme) low carb diet is beneficial to reduce estrogen and Insulin and testosterone.