Legal Question in Wills and Trusts in Illinois

It depends on how Father held title to the assets. Any assets held in joint tenancy with the one daughter, or with a beneficiary designation in favor of the one daughter, will belong to the one daughter upon Father's death. Otherwise, the laws of intestacy in Illinois would provide for Dad's children to share equally (presuming Mom is deceased). If the one daughter were Father's caregiver, she may be entitled to claim funds as caregiver.

Without a will and assuming that there is not a spouse, under Illinois law the estate should be divided among the children and the descendants of any deceased child. The caregiver may be given certain rights, but certainly you should be seeing a probate attorney to protect your interests. The more time that passes, the less likely you will have a good outcome.