If they are little white bumps on the main stem, this is perfectly normal and of no concern.
If you pick them off you will cause damage to the outer layer of the stem, an injury, where disease can attack.
Picture of the "white bumps" would help, but if it is what I have described, as being on the main stem/trunk of the plant, no issue to stress about.
In nature, if there is a build up of humus/compost/dead leaves around those bumps, cannabis will actually grow roots from those bumps.
Hope this helps..... Organoman.
PS - if you are really keen and you want to do and experiment ...... if the soil in your pot has sunk, you could "top dress" your pots with some more soil/compost mix and see if she grows roots. This "top dressing" will not harm your plant/s.