I really can't put it in any other terms that will reassure you. Go back and read what I told you the first time. Keep reading it until you calm down.

Who put the security deposit down is irrelevant. What matters is who is on the lease contract.

I'm fearful that I may come home to find the locks changed and my stuff on the street!
If she's that much of a pill, maybe you want for this to happen so you have justification to sue the hell out of her, cost her serious money, and make her miserable.