Hello Jeff,
Margaret (bd. 1753) was the daughter of Charles SHIMMIN and Catherine QUAYLE who md. in German 4Apr1752. Margaret md. John CRELLIN in German 27Feb 1781.
Her siblings were -
Catherine (bd. 1757), md. Philip KILLEY in 1779.
Elizabeth (bd. 1757). d. 1760
Ann (bd. 1764). md. Philip QUIGGIN in 1790.
John (bd. 1766) d. 1809 in England. md. Elizabeth WATTLEWORTH in 1796, and Catherine WATTLEWORTH in 1802.
Elizabeth (bd. 1767). d. 1784.
Isabel (bd. 1773). md. Hugh McNab in 1793.

Margaret, Catherine and Isabel are all mentioned in the parents wills.
Catherine and Isabel are not included in the IGI baptisms.
Margaret’s baptism is in the IGI, but her parents are given as Charles and Margaret QUAYLE.
As there is no record of such a marriage, it’s fairly certain this is a transcription error.

Patrick CRELLIN’s siblings were -
John. bd. 1781.
Catherine. bd. 1782.
Eleanor. bd. 1785.
William. bd. 1792.
Thomas. bd. 1796.

Regards,
Ed.