my mother past away in 9/2011 and had no will. she has 2 house that have a balance on them and also had debit. how long can we wait to open a probate

Dear Lorena, My condolences on your mother's passing.  Now concerning how long you have to wait to open probate - Lorena you have already let four months pass you by....you could have opened probate as soon as the coroner or hospital provided you with the certified death certificate.....so run do not walk [to a probate attorney's office] & go handle the business.  I imagine the mortgage companies will not deal with you unless and until you have what's called Letters of Office in hand - those are something you get in the process of probating the estate.  The creditors (you stated your mom had debt) will have 6 months in which to file claims against the estate and the clock begins to tick upon your receipt of the letters of office (wherein you are named executor).  Hope that helps and good luck with everything.