সিয়াম [ রোজা ] সম্পর্কীত

I used to keep my broken Ramadan fasts and 6 days fast of Shawal on the same days. I used to say two different niyahs. But now my sister in Islam says that I cannot keep fast for two niyahs. These fasts  should be kept separately. Now what would happen to my previous fasts. Do I need to do anything regarding those? Will my broken Ramadan fasts that I kept be valid?

Question:icdbd-QA/0015 Fasting became obligatory on me at the age of 14 when I became baaleg. due to ignorance and also