He's sound asleep when she comes back, so she commits the spell on the scroll she 'borrowed' to memory. It's simple, in principle, allow someone to pick up a language quite quickly if they hear it. Another trip to the capital tomorrow, perhaps, do a bit of shopping, let Skellig acquire the local language while they're there.

When he wakes again, she will have put THAT dress on again, in an attempt to get him used to it. She's also rigged a small container of sand and set it on the table with a writing brush sized stick for Skellig to practice writing with.