This is amazing, and very confusing. We definitely have the same family tree, but this is what I have discovered....
By purchasing a copy of Charles Robert SIMS' birth certificate, I found that William Thomas SIMS was born in St John, New Brunswick, AMERICA (now CANADA)in c1834. He married Caroline COX c1853 in LONDON. Caroline was born c1835 in Berkshire, ENGLAND. Their other children were Matilda born c1856, George c1858 and Sarah c1861.
Charles did indeed marry Lucy Ellen WELLS, and eventually moved to Kalgoorlie WA.
So we seem to have Caroline COX, married to, and had children with Thomas AND William SIMS...brothers, maybe? I have found a record of the marriage between Thomas and Caroline (Free BMD)c1853, in London, and also found the record of Thomas, Caroline and Caroline M SIMS' arrival in 1857. So I could see the corresponding matches with my William and Caroline SIMS. I've been trying to find records of William's birth in Canada, with no luck, yet.
We have a very large branch of the SIMS family here in WA, as Charles and Lucy had eleven kids. I'm actually in the process of organizing a family reunion, for the 27th of January, next year.
Please contact me at firstname.lastname@example.org
, so hopefully we can unravel this puzzle. This is so very exciting, and very curious.
Hope to hear from soon,