Hi, no, there are a few mistakes: (and now you've edited it, there are even more!)
Are any of your siblings married? If so, who is? Yes, some are. I have four siblings who are married.
Normally we ask questions in the plural.
'If so' is idiomatic.
You can't use 'he is' and then say 'four are', particularly if some of them are sisters.
(edit for the second line)
The first one that married was my brother Hamza, then Emad, then Moath and the last one was Mohammed.
It's more natural to talk about when they got married, and therefore use past tense if you are saying it in that order.