Can a collection agency issue a lien on a property if my name is on the deed but not on the loan? Also her name is not on the unsecured loan

If they obtain a judgement aganst you they can put a lien on any property you have ownership interest in (meaning you are on the title). Whether there is a loan on the property that is not in your name is immatierial.

We concur with ScottGem although depending upon your jurisdiction it may be referred to as a writ as opposed to a lien.

Generally, the writ/lien can only attach to your interest in the property. Therefore, if you are a half owner the writ/lien attaches to your half and not the other owner's half.