AHA! But great job of ruling out the paranormal involvement! Yes, I agree she stepped over the boundary there. Intentions were good, but she really should have shared with you.***UPDATE***
So come to find out it was my SIL. She did it to protect us because she felt a sudden urge to pray over pour house one day while I was at work. She didn't tell us because she didn't know how to. She didn't think the crosses would show up. She used salt water. While I understand her reasoning, I don't appreciate her going through our home including our bedroom.