He pauses, then nods once, with his free arm moving back to support the sleeping infant. Lowering himself onto his knees to serve as a better cradle, he gives enough room for her to be able to administer the medicine, though still keeping a watchful eye for the elixir having any... untoward reactions.

"Just... try an' be careful."

If it came to that, he could probably fix it. Right now, he's putting his trust in someone who he's believing to be a friend.