Beatties in Killead

Seeking information on my Beattie/Gilchrist/McBurney/Manderson/Mulholland families of Killead Parish. Thomas Beattie (b. ca. 1648) immigrated from Ayrshire, Scotland to the Templepatrick/Ballyrobin area. He is found on the 1669 Heath Money Rolls. He died in 1717 and is buried in the Carmavey graveyard with several descendants. There is a generation (or maybe two?) between him and our ancestor, Thomas Beattie, b. about 1750 in Killead parish. This Thomas Beattie married Margaret Gilchrist. They had several known children (and likely more due to the gaps in ages):
Thomas - b. ca. 1777. He was in the Irish Army from about 1805-1813. I know nothing more about him
Mary - b. 1780. She married Samuel Molyneux. Their son, also a Samuel, and several of his children are buried with Thomas Beattie, the immigrant, in Carmnavey. She and Samuel lived in Killead parish.
John - b. 1782. He is our direct ancestor. He may have been a William John as that is what he named one of his sons. He married an unknown Eliza b. 1784 in Ballymena. He immigrated to New York, USA about 1806. He returned to Antrim about 10 years later and married the unknown Eliza and brought her back to America. Eliza had a sister, Mary, who married William Edmiston, but this is the extent of my knowledge about their family. Mary was b. about 1800. In a letter to our John in 1837, it is mentioned that Eliza's family had left the Ballymena area.
James - b. about 1790. He was still unmarried in 1837 per the letter from Antrim to John in America.
Jane "Jennie" - b. 1795. She married Thomas Henry McClure and d. 1820.
Margaret - b. 1798. She married David McClure, brother to TH, above. She and David lived their adult lives in Duneane parish and are buried there. She died in 1885.

Thomas Beattie (b. ca. 1750) had 2 known siblings: Jane "Jenny" b. 1762 who married John Molyneaux, a brother to Samuel, above, and Sarah, b 1761 who never married and lived to be 100 years old! Sarah is buried with her immigrant ancestor and other relatives in the Beattie plot at Carmavey. Due to age gaps, there are likely more siblings.

Margaret Gilchrist (b. ca 1755), who married Thomas Beattie b 1750, had at least two known sisters, Sarah (b 1745) and Jane (b 1760). Sarah Gilchrist married Thomas McBurney. Jane married James Mullhollan(d). Thomas McBurney died in Antrim in 1772. In 1784, Sarah, with her unknown mother-in-law and her 4 children immigrated to Philadelphia, PA USA. Daughter Barbara and the mother-in-law died shortly after arrival in PA. Daughter Elizabeth McBurney married Andrew Manderson in Philadelphioa in 1795. The Mandersons were from Crumlin. Sons James McBurney and Thomas McBurney (who took mother Sarah with them), migrated to Steuben Co NY about 1797. James McBurney returned to Antrim about 1806 and persuaded his cousin, John Beattie, to return with him to America. Jane Beattie and her husband, James Mulhollan(d), immigrated to Washington Co. PA. Sarah Gilchrist McBurney died 1829 in Steuben Co NY. Jane Gilchrist Mulhollan(d) died 1837 in Washington Co PA.

About 1798, Thomas Beattie (b 1750) removed from Killead to Artreshnahan, near Randallstown. His farm was next door to David McClure and family. David McClure owned an inn in Randallstown. It is believed that Thomas Beattie died about 1799. In 1807, Margaret Gilchrist Beattie sub-let part of her farm to William Collins. Son Thomas was in Scotland with the Irish Army and son John and gone to America. Margaret is believed to have died about 1824. It is coincidental, too, that William Collins' daughter, Jane, would marry Thomas Henry McClure after Jane Beattie died.

Any information on any of these family members would be appreciated. I don't know the burial locations of Thomas and Margaret Beattie. I'd like to find additional siblings and any additional information about these family members. I call the unknown Eliza who married our John Beattie "Elusive Eliza" as I have never found her maiden name, nor a marriage record for them. I'd like to identify her family. I'd also like to discover more information on the Gilchrist family. Thank you!