Can you help me find cases in Illinois that are on point and similar to this case. I'm writing an office memorandum. To help find cases we are supposed to search and re search "what are the elements of proof for gift" and use that to help find Illinois cases.

Writing Assignment 1: Your supervising attorney has just met with a client and has asked for a memorandum explaining the statutory and case law pertaining to their problem. The client's father just passed away in Illinois. The client is his only child and would inherit under the Will and laws of intestacy. The father was not married. However, the father had a checking account that was designated joint tenancy with right of survivorship with the person that he was living with. All of the funds that were ever deposited into the account came from the father's pension. All expenditures by either party were to pay for the father's necessaries. The other person on the account withdrew all of the remaining funds after the father died. Is there any legal basis to pursue the money on behalf of the father's estate or the client