A thought re everyone with the same name.
Have you checked the 1861/1871 or 1881 census to see which Ryans are together? John and Sarah? John & Ellen? w/ son Stephen.
On the second marrige registration, Bridget's last name looks like Fahey. The ages are reversed for the bride and groom but I think it is the same people.
I think this is Stephen Ryan's first marriage:
Stephen Ryan, 26, b Canada, living Gratton, s/o John Ryan & Sarah Gallagher, married Ellen Beahan, 21, Canada, Gratton, d/o David Beahan & Margaret Power, Witn: Michael Power of Gralton & Catherine Ryan of Sebastopol, 10 Nov 1879, at Eganville, Renfrew, # 009622.
Looks like parents are John & Sarah.
I think both registrations are for the same people and someone mixed up the names.
Did not find a death for Ellen Ryan but an Ellen Behan, 28, died 14 Jun 1883, no cause given, in Eganville. Same person? Does it matter?
Only birth listed on Ancestry.ca is stillborn,male, b Feb 1882 w parents Stephen & Ellen.
The more I look, the more confused I get. Too many Ryans!
Hope you get it all sorted out. Good Luck!