Correct. The "h" renders the "g" silent in Irish. In the 1920's, after winning independence, the Irish Free State tried to bring back Irish as a spoken tongue. To help, they "cleaned up" some of the more daunting aspects of Irish spelling. Thus
Maighread became
Mairead, both pronounced "ma-RADE."
(My source of information is my Irish mother, taught Gaelic in school growing up.)