I have a Jesse Gardiner b c1858 in Bisley, son of Henry Gardiner b c1832 and Elizabeth Phelps.
I am wondering if this could be the cousin Jessie of your Selina. I don't know Henrys parents at the mo so I can't tie any of the Gardiners together.
Do you know if Reuben had any brothers or sisters? I do have a Thomas Gardiner b c1803 married to a Dinah Gardiner (Cousins I believe). Her parents were John Gardiner b c1794 and Margaret NK B c1799 Bisley but again no parent s for Thomas as I have yet to decide wether he is Samuel Gardiners or Giles Gardiners son.
Do any Gardiners ring a bell to you. I have to say they did like marrying into each others familys lol. Still, it makes for an interesting family tree
regards
Karianne