Is it obligatory to make up for the missed days of fasting in Ramadan for someone who reached puberty and was unaware of the obligation to make them up, while not remembering the number of missed days?

Puberty for a female is not limited to menstruation; rather, it has other signs. The questioner must make up for the Ramadan fasts she missed after verifying one of the signs of puberty. She must continue making up the fasts until her obligation is fulfilled. She is also liable for a compensatory expiation (kaffarat al-ta’khir) if she was aware of the impermissibility of delaying the make-up fasts. This expiation is 750 grams of the staple food of the country for each day, to be given to the poor. However, if the delay was due to ignorance, forgetfulness, or a legitimate excuse, then no expiation is required of her, but only the make-up fasts. Fasting is not obligatory until one of the signs of puberty is verified. If you doubt the occurrence of the first sign, then fasting is not obligatory, because the default state is not being pubescent until it is proven with certainty.