I don't know of any Gaelic form for that name.
You don't. It is not a Gaelic name.
Anndra is the Scottish Gaelic equivalent of Andrew.
if it is a name it is the same in every language
Arielle Kebbel's birth name is Arielle Caroline Kebbel.
Arielle Hakian's birth name is Arielle Effrat Hakian.
Arielle Dombasle's birth name is Arielle Sonnery de Fromental.
Arielle Vandenberg's birth name is Arielle St. Cyr Vandenberg.
For what it's worth, the name Zachary is called Sgàire[skah.ruh] in Scottish Gaelic.
The name Martin can be translated as Máirtín or Mártan in Irish; the Scottish Gaelic is Màrtainn.There are not many names that translate perfectly into Irish unless they are biblical like Diego in English is James. We can translate that as it is biblical.Séamus.
Names don't 'translate' unless they have a historical connection with the Gaelic cultures or are in the Bible.
Yes there is a Arielle in this world and is meant for a female name.
Woulfe's "Irish Names for Children" gives Séarlait as an Irish Gaelic form of the borrowed French name.