1850 - Joshua Jr and family -- Home in 1850: District 1, Whitley, Kentucky, USA; Dwelling Number: 392; Family Number: 392
1850, Louisa Caddell and family -- Home in 1850: District 1, Whitley, Kentucky, USA; Dwelling Number: 261; Family Number: 261
So, they were living in the same place, just not right next door (I still didn't find them in the one document - I have two tabs open, one with her family (mis-transcribed as Luinnda Caddell), and one with her father (mis-transcribed as Josh Maron)).
Angela, I don't think you will get better than this, unless you somehow find a baptismal record.
Sometimes we just have to take the bulk of the circumstantial evidence, and say "this is the best proof we have".