Father Passed Away, House Still In His Name, I Inherited His 401(k). Mom (not Married To Him) Is Taking My Money And Draining Me— What Are My Legal Options?

I’m 20 now. My dad passed away two years ago when I was 17. He didn’t have a will, and he and my mom were not married at the time of his death.

I was his only next of kin, and the beneficiary of his 401(k), which transferred fully into my name when I turned 18.

When he died, my mom and I were both living in his house. She stayed, and I stayed too because it felt like the right thing to do and I wanted to keep the property in the family.

Over the last two years, I’ve used more than half of my inheritance to pay down the mortgage on my dad’s house, plus some to buy my mom a car and help with bills.

The problem:

Probate was never opened, so the house is still legally in my dad’s name.

My mom continues to claim the house is yours and says “we should finish paying it off.”

She also takes money from me, opens my mail, drives my car without permission, and sometimes puts bills in my name.

She has a drug problem and frequently begs for money, making it difficult for me to even afford utilities.

I’m realizing I made a mistake mixing my inheritance into this situation, but I don’t know how to fix it now.

I’m his biological daughter and sole next of kin. My mom has no legal relationship to him.

I want to move out and protect myself, but I don’t know what steps I should take legally regarding the house or probate.

My questions:

1. Can I open probate myself and have the house transferred into my name as his heir? Is probate like a difficult process?

2. Does my mom have any legal claim to the property since they weren’t married?

3. Since my dad passed away two years ago and probate was never opened, how long can a house legally remain in the name of a deceased person before it must go through probate or transfer? What happens legally if no one acts?

Location: Illinois