a tree at ancestry calls
Eliza, John, David, and Samuel half-siblings of William Rea. Their parents are children of James Rea and Mary McDonnell. James is William's father, but his mother is unknown on the tree.
Eliza is said to be born 26 JAN 1870 • Belfast No. 10, Ant, Ireland. No information for the others.
edited - disregard or take with a grain of salt all of the above, since William turns out to be 50 years older than Eliza. Hard to be half-siblings with that age gap. I just searched for "William Rea, d. 1906." I'm sure there were a few William Reas around, and the tree owner might have just grabbed the first one they saw.
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this is correct though:
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Belfast Newsletter, October 26, 1906
REA - October 24, at Mourne View, Ballynahinch. William Rea, late of The Haw, Ballycreen. His remains will be removed from the above address, for interment in the family burying-ground, Saintfield Churchyard, this (Friday) afternoon, at one o'clock. Friends will please accept this (the only) invitation.
[signed, or placed by] J.B. Patterson