Don't worry too much about what kind of message you convey. Try to figure out what response she really deserves. She says she cares about you (I won't use her word "love" because it is open to a wide range of interpretations). She clearly is trying to be nice with you. You say you want to validate her feelings and be friendly. Then do just that. Don't do it because of how she might interpret that, but because it is the nice thing to do. Tell her you are grateful for her feelings (do not reciprocate though), tell her she does not disturb you, tell her she must be in a difficult situation with the car etc.
That way you allow her to keep the communication open, if she wants. You do not have to keep it open. Let her contact you.
In your post it is not clear whether she is asking about your trip. If she has, tell her it is great (no detail), but be brief about it. No pics. If she hasn't asked, don't tell her anything.
