Yup A clean cage is a given anyway this will help avoid infection while in season
There are 2 points to this.
If you do not breed from a ferret there may be problems with her in later life, Hips etc
If you do not do something to bring her out of season, she keeps losing blood and this may lead to Anemea which can kill them.
Loads of people are happy with the jab ,you may need more than one jab per year if she has more than one bout "in season" My view is a Vasectomised (not neutered) hob is the best way but not every one has this choice.
You may wish to hope for the best , but in m