Legal Question in Wills and Trusts in Illinois

This is a "don't try this at home" kind of situation. You should consult with an attorney.

I agree with Ms. Prihoda. Seek out an attorney.

Owning property in joint tenancy directly conflicts with your desire to have the property split upon the first person's death. Your "agreement" may not be upheld.

Consider instead changing ownership from joint tenancy to tenants in common. Again, seek out an estate planning attorney to discuss further options.

By definition, joint tenancy provides for the survivor to succeed to the property regardless a will, trust or other estate planning document and probably regardless of any contractual agreement. Either your agreement will not be enforceable or you run the risk of the matter being tied up in a legal challenge and costing everyone far more than would be spent now for you to see an attorney now. There is far more chance of working this out now by agreement than there will be should the above situation arise. Moreover, do you want the resolution dependent on this artificial thirty-day requirement (which is usually used in estate planning to avoid issues that arise in common accident situation) or do you each want to make sure that whoever you want to benefit does eventually benefit?