Is there a supplication to induce menstruation and relieve distress for an unmarried girl whose period has been delayed for two months and who fears taking medications?

There is no maximum limit for the period of purity between two menstrual cycles. A woman may remain pure for a year or more until she menstruates, or she may not menstruate at all, or she may menstruate once every two years. There is no specific supplication that makes a woman menstruate every month, but she can turn to Allah with any appropriate supplication for that purpose, while observing the conditions and etiquette of supplication.