Does a woman's period change after she has a tubal ligation?

No. Periods should not change after tubal ligation. The reason some women report menstrual changes after tubal ligations may be a coincidence or because of discontinuation of other birth control methods, such as the pills, which tend to control the menstrual cycle well.
No. A tubal ligation does not effect a woman's periods. As time goes on and a woman ages, menstrual cycles may change due to hormonal changes, but not because of the surgery, if changes do occur, it is important to let your physician know so that any irregularity can be further evaluated.