Welcome! Galen grew up in the Highever alienage, so there may be some small chance of them encountering each other -- his sister was also a servant at Castle Cousland, so there's a chance that he may have been near by. He trusts any humans as far as he can throw them, which...given that he's a skinny elf boy, is not really that far. But it might still be neat to have some kind of backscene. He left Highever about two years ago and has been living with the Dalish for nearly a year now, but they will be in the same group eventually, anyway!
I also have bethe, who is a mage and unlikely to have ever met Jill before, but there is ronain, who is a knight of Redcliffe and may have encountered Jill before if she's been to their town on messenger business.