User blog comment:FairyRaven/Fairy Tail Chapter 365: Fairy in the Jail!, Review and Commentary/@comment-112.198.77.217-20131228150841/@comment-7418318-20131229082012

Whoever said that the receptibles of the seal have to be prominent.

And we don't know if Ultear is alive. Yes initially she "only" turned into an old woman, but for all we know she might have died of old age since then or fell down the stairs to break her neck or a plentitude of other possibilities, including Tartarus somehow managing to track her down.

But considering how Jellal and Ultear joined the council at roughly the same time, I think it's unlikely that both of them would have been chosen in the short time they were part of the council. Most likely Face is rather old and when one person with the seal dies, or shortly before they die, the seal is moved to a new person. It's unlikely that two seal-bearers died just at the moment when Jellal and Ultear came into the council.