If my 13yo daughter previously had no problems with bed wetting but has had two episodes in the last month should I do anything?

Probably yes. So-called secondary enuresis (onset of bedwetting in someone who has not been doing that for a long while) especially in a teenage is worth exploring. In girls, a common cause is a bladder infection, so a visit to the pediatrician or family doctor would be a good start. For a full physical exam, other common causes are increased stress.
Probably no. Two islated wetting occurrences may just be odd or random. Get urine checked if any more episodes in case of uti, diabetes insipus or mellitus. Try and find out if she drank huge volumes and forgot to toilet before bed. Any stress at school or home? Was she overtired? See primary care dr if wetting continues or has other symptoms + may need uktrasound or medication. Prognosis is usually good.
See MD. Most likely this is not a medical problem. However, it certainly merits a quick evaluation by your primary md and a urinalysis to rule out infection and ensure that there are no other concerns.