Is "Is it for me?" another possible translation?
No, that would be "Is het voor mij?".
Is it of me is a more like for like translation which coverts to is it mine.
Does it also mean "from me"? Google Trans thinks so.
don't trust google
it could mean that, however a Dutchman would say "Het komt van mij" "It comes from me/I am the origin of it"
yes, it could
Could "is het mijn" be another translation for "is it mine"?
No, that does not work. Either: