Nixons from Ireland to Philadelphia approx late 1800's

Hi I am looking for any information on four Nixons that immigrated from Ireland to Philadelphia.

Margaret Nixon born 1863 Ireland listed as a dressmaker in the 1880 us census in Philadelphia.

Sarah Nixon born 1857 Ireland listed as a dressmaker in the 1880 us census in Philadelphia.

George Nixon born 1859 Ireland listed as a Shirtcutter in the 1880 us census in Philadelphia.

Mary Jane Jamison (nee Nixon) born in 1845 in Ireland listed as a dressmaker in the 1880 us census in Philadelphia.

Mary Jane married in 1875 in Philadelphia a William Jamison who was born in Ireland in 1835.

Mary could've possibly immigrated earlier then George, Sarah and Margaret. Any information would be greatly appreciated!!

Thankyou

Kylie Bowles