I haven't identified Robert definitely in 1851 yet, but the IGI has 2 possibilities:
Robert Fry, son of Robert Fry and Ann, b. Culmstock, Devon, 1 Apr 1832.
Robert Fry, son of Thomas Fry and Jane, b. Culmstock, Devon, 24 Sep 1835.
These are extracted records, ie. copied from parish registers, and normally reliable. The second one is a better match for age, but I have only found the other one so far on the 1851 census.

The IGI also has a user-submitted marriage record between Robert Fry, son of Thomas Fry, and Jemima Trenchard, dau of John Trenchard, in Pitminster, Somerset,in 1860. User-submitted records vary in reliability, and the marriage date looks like an estimate, but I looked up Jemima in the 1851 census and found this entry:
HO107/1922/106/24 - Pitminster, SomersetJohn Trenchard Head 61 Dairyman b. Dunkinwell, Somerset
Betty Trenchard Wife 57 b. [...]liscombe
Jemima Trenchard Dau 13 b. Upottery
Jonathan Oaten Son-in-law 21 Ag Lab b. Pitminster
Harriet Oaten Dau 21 b. Upottery
Janet Oaten G Dau 4m b. Pitminster
She would certainly fit the census details for Mrs Jemima Fry.
Just found a possibility for Robert, aged 13 and working as a farm labourer in Culmstock - index says Fay, but I read it as Fry.
Rambler