It depends. For the most part yes as long as you report everything correctly, then you should be okay. I would recommend that you put all deposits and pay all expenses of the estate from the estate account. It is not a good idea that you put into different accounts.
Another to keep in mind, even though you are the only child, did your mother have a Will, was your name on everything she owned as a joint owner.
My one concern is on the house you sold, was this in your mother's name only, or were you a joint owner with her? How the house was held, would make a difference in how the sale should be reported for tax purposes. If you were a joint owner on the property, yes the property automatically converted to you only, but then when you sold this you may have to report this as a possible capital gain. If it was not your primary home and it sounds like it was rented, then you would have to report this on your return as the sale of business property (since it was rental property). I would seek advice on reporting this, there are a lot of questions that should be answered to determine the proper way to handle the proceeds from the sale. It is not considered inheritance if your name was on the home.
If she did not have a Will and you were not a joint owner on all of the property with your mother, you should really seek legal advice. There are intestate laws (someone who dies without a Will).
I cannot give you advice on what to do, but what I can say is I would seek out a professional to answer your questions before completing your taxes.
