First, you need to talk with a probate attorney.
Second, just in case you need to pointers...Probate usually means that the mother died without a will. When that happens there are state laws that governs who things are done.
Suggestion number one - make out a will.
Suggestion number two - learn about the probate laws and what they mean. That means that a judge will be doing the deciding. Most of the fees are set by statute, so it is doubtful you will be ripped off.