I have been using my great grandmothers surname on social media to keep my profiles relatively "private". I have been using Ó hAnnracháin, however, I was a "bitesize" blog post about using your surname and getting the literal translations.

my last name is "Hawkes" so I was going to use "Seabhaic", but when speaking with a near fluent speaker, she suggested I use "Mac An tSeabhcóra" as the usual form. She suggested i double check to make sure if the masculine noun would take a 't' in the genitive.

she also suggested the pronunciation as "mawk uh Cha-kor-uh"

any suggestions?

thank you all

Yes, a masculine noun which starts with an "s" followed by a vowel would take a "t" in the genitive case as you were shown, so Mac an tSeabhcóra is correct for "son of the hawker/falconer" (note that seabhcóir means "hawker" or "falconer", not "hawk"). In his The Surnames of Ireland, MacLysaght mentions that the name Falconer/Falkiner is an English name common in Ulster, but he doesn't indicate that any Irish translation of it was ever made in this manner. He states that it was "often used as a synonym of Fealy or Falvey in Kerry and of Faulkney in Mayo", and also that the "usual spelling in Co. Derry is Faulkner".

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I'm not a native (or entirely fluent) speaker, so be sure to wait for confirmations/corrections, especially for tattoos.

"mawk" is strange.
Especially in surnames the pronunciation of Mac is short, "muhk" or even shortened to "uhk"

"Cha-kor-uh"
Rather "Tyow-ko-ruh" ("Chow-..." in Ulster)#

BTW, "an Seabhac" is the pen-name of the Irish writer Pádraig Ó Siochfhradha.

GRMA for the help, you two. very much appreciate it