When I reached puberty, I was commiting shirk and also fasting without praying, so my fastings were nullified due to this, and I also missed fastings later on due to pregnancy and breastfeeding, what shall I do with the missed fasts when I reached puberty? As for pregnancy and breastfeeding missed fasts, shall I give money to poor people as a compensation? May Allah reward you.
Shaikh Waleed Boghdady:
Regarding the first part of the question, no you do not compensate these days. But you need to try to fast as many voluntary fasts as you can, for example the three white days of each month, Mondays and Thursdays.
As for the days you missed due to pregnancy and breastfeeding, according to the opinion of several Companions, including Ibn Abbas and Abu Hurairah and Anas Ibn Malik a woman who is not able to fast due to pregnancy or breastfeeding is not requested to fast the days she missed as a compensation. She only needs to make a fediyya of feeding one meal to a needy muslim for every day she did not fast. So you need to try to calculate them and to feed one poor Muslim per day you didn’t fast, so for example if you missed 60 days due to pregnancy or breastfeeding you have to give away 60 meals. This is also the opinion of Imam Al-Albani.