S.E.
Yes it can be related to teething. The saliva becomes more acidic during teething and can cause changing in digestion. Also look out for diaper rash during these days.
If the diarrhea is mild, up her liquids so she stays hydrated, you may even consider an electrolyte to help (you can give it to her in a bottle or mixed with formula). If it becomes more severe, call her pedi to make sure she doesn't have a bug that's going around.