This article says that Myrcella is in line to inherit the iron throne before Renly. My understanding is that Myrcella has no inheritance rights to the iron throne because of being female.Softlanding (talk) 21:31, June 21, 2016 (UTC)
Thank you for pointing this out, it is indeed in error.
Royal succession is different from regular succession; women are not excluded from the line of succession, but put behind all possible male heirs. Myrcella thus ranks behind Renly in line of succession, though she does rank somewhere.
There was even a scene in season 1 in which Loras explicitly, and accurately, stated that Renly was fourth in line to the throne behind Joffrey, Tommen, and Stannis.