I wake at 4:15 AM for Fajr, but due to family circumstances I usually can't sleep before 11:30 PM, so I sometimes miss Fajr. Should I take a 1–2 hour daytime nap or sleep after Fajr? Since morning is a time of barakah, which is better according to the Sunnah for me?

Ustadh AbdulAziz al-Haqqan

You can do both, whatever is more suitable for you.