My wife and I are going to separate and divorce. We bought a house 7 months ago and knew we had major problems in our marriage. I had her sign and notorize a letter stating if we separated she would leave the residence and I would be responsible for it. Can she stay until court or does she have to leave since she signed the letter ?

If her name is on the deed, she can stay there, and the burden is on you to try to enforce a notarized statement. Without any real legalese spelling out exactly when she had to leave, it's going to be tough for you.

If, as you tell us, the letter says " if we separated she would leave the residence", that doesn't really cut it. Until one of you ceases living in the residence, you haven't separated, have you? Thus the letter, if it can be termed a binding agreement, doesn't have any present effect.

It's like saying that "we agree to agree". Doesn't really mean much.

Having the agreement notarized does nothing except confirm that she signed it. A notary is just a professional witness.

Whether this agreement can be binding is a large question that would require a court to decide. So you need to file for divorce and ask for a legal separation. As part of the legal separation you can ask that she be ordered to move out as per the agreement.

The letter may not even be honored in court, so it has to go to court, and she does not have to leave, until she wants to, or a judge orders it.