Hi Debora,
I don't remember how many posts you need to have before you can use the PM system but you probably do not have enough, so I will send you a message.
I do not have all the earlier generations of Quigleys on my tree as I usually do not do more than note the parents of spouses, unless I suspect there is another link in earlier generations. Such as in your case the Sloane marriages a couple of generations apart. I took the info from the tree of Una Bobby, who I have corresponded with occasionally. Una has my Grahams in her tree but only named the direct Quigley ancestors from her family so your Bannister was not included. There were other trees that I didn't look at.
Re my family, if you happen across these 3 people then I would love to have a photo of their tombstones
Issamenia Graham nee Quigleyt lived to be 99 years old so presumably died in 1963. Her granddaughter Lilly Graham (dau of James) was with her when she died. Lilly wrote that Issamenia is buried at Glenavy, where the Quigley family lived, as were her sons William & Lester Graham. (Lester is aka Alexander).
Cheers
Linda (NZ)