HELP!! "Subject To" Questions

[Patrick Wall]

My wife & I are new investors. This is  our 1st deal & we are unsure of how to proceed the right way.

An acquaintance of ours is the beneficiary of her mothers home who passed away 2 years ago. She continued to make payment on her mothers home for a year & then could no longer  keep up both hers & moms mortgage pymts ( She has missed 12 payments).  The houseis currently set for county Auction on May 10th.  She has agreed to sell us the house "subject to" for the remaining balance of the loan so that her moms house won't have to be sold  in that manner. 

Our confusion is the following:

Can we negotiate the  missed payments with the mortgage co? If so, How without causing an issues?

Do we need to have a real estate attorney to stop the foreclosure or , will paying the back payments do that?

Any feedback / help would be Greatly appreciated!!!