She already has a will. Your mother's will should accomplish her objective of leaving her estate to you, but her estate would be subject to probate. Probate is the process whereby the state examines a deceased's will and determines where the assets should go. When an estate is subject to probate, there are statutory fees that cannot be avoided. Furthermore, her assets would pass to you immediately without the state getting involved and delaying the process.
Many people have the misconception that living trusts are only for the wealthy.
As you can see by your mother's estate, even those with modest assets should consider a living trust. A qualified estate-planning attorney should draft a trust. With tens of thousands of dollars at stake, it makes sense to invest a little to get a trust set up right. I moved my IRA from a bank to a stockbroker earlier this year and I am not pleased with the broker. He has made several changes to my account, but he always seems to pick stocks that are expensive and he charges me commissions every time he makes a change.