Yes, Gilbert and Cathrine are Brother & Sister,

Jon Christian [Will] and Joney Skinner [Will]
Married: 27 NOV 1718 Andreas

Children: (named in their parents Wills)
Edmond Christian 14 APR 1718 Bride father : Jon (named in his Grandmother‘s Will)
Gilbert Christian 02 APR 1721 Andreas m. Mary Corkill 18 JUL 1747 Andreas
Jony Christian 08 NOV 1724 Andreas m. Thos Mylecharane 25 AUG 1753 Andreas
William Christian 17 JUL 1726 Andreas
Cathrine Christian m. John Radcliffe 14 JAN 1758 Andreas

Thank you so much for all these look ups very much appreciated,

Averil