User blog comment:Omega natsu2/Chapter 365: Fairy in the Jail!, Predictions./@comment-24257713-20131219164540/@comment-7418318-20131219211559

Maybe Doranbolt gave them back the stuff that was confiscated from them on their arrest.

And since Caelum is a silver spirit, there might be more than just one, like there are multiple (multitudes really) of Canis Minor keys and spirits.

If the silver spirits don't have the power to move away and choose a new master on their own, she could form new contracts with her old spirits if she got the keys back. And while it's unlikely, it's still possible that silver-spirit contracts are less restrictive and thus weren't broken when she was arrested and convicted.