Salaah

Performing qadha salaah in the masjid

Q: I have heard that one should pray Qadha prayer in solitude so that it should not be revealed to anyone that one is praying Qadha prayer. Is this true? 

If so, then there is a problem that in a house where one does not get solitude and it is not possible in the mosque, then what should one do in such a case? 

Then can one pray Qadha prayer in front of the family members or in front of everyone in the mosque.

Folding one's hands in the last rakaat of the sunnats of fajr while sitting and performing salaah

Q: If sitting down and performing sunnat of Fajr, after the last sajdah of the salah, one puts their hands up again for Surah Fatiha, but remembers before reciting anything, and then goes to continue tashahudd, should a qadha be recited for this salah? And should one have made sajdah sahw in such a case .