Is fasting obligatory for one who was born in the past Ramadan and has not yet experienced menstruation, and now, after a year, she has started to see intermittent brown spots and some red blood spots that stop for a day and then return?

These brown spots, accompanied by specks of blood after a long period, are considered menstruation. Therefore, one must refrain from fasting and praying during their presence and resume acts of worship once they stop. If the total days of bleeding exceed 15 days, then anything beyond that is considered istihadah (non-menstrual vaginal bleeding).