The Catherine (or Elizabeth Catherine) Robar/Robert who married Christopher Veno/Vienot/Veinot in 1761 was not a daughter of Abraham and Elizabeth Catherine Robar.
Referring to the Shankle transcriptions of the Lunenburg church records as well as Smith and Smith's 'Nova Scotia Immigrants to 1867' you can see that the Catherine in question arrived initially in Halifax on the Betty in 1752 together with sisters Elisabeth and Jeanne and brother David (18). Abraham (30), his wife Elisabeth Catherine and infant daughter Elisabeth arrived at Halifax in 1752 on the Speedwell. They all originated in Montbeliard, France and it is possible that the Catherine in question was a sister to Abraham but I haven't seen the data to support that (although it may very well exist). A Jacque Veinot (15) travelled to Nova Scotia on the Betty in 1752 with his parents Leopold and Jeanne and brothers Christophe and George. They were of course also from Montbeliard.