As a girl's name this is a pet form of Jacqueline, as in the case of Jackie Kennedy Onassis (1929–94). It was originally a boy's name, a pet form of Jack. The racing driver Jackie Stewart (b. 1939) was originally named John Young Stewart.
Irish: shortened Anglicized form of McCalvey, which is recorded as a variant Anglicized form of Gaelic Mac Giolla Bhuidhe (see McElwee), although Woulfe treats it as an Anglicized form of Gaelic Mac an Chalbhaigh, possibly from calbhach ‘bald’.