Legal Question in Real Estate Law in Maryland

I suggest you just continue to make the payments unless you want to inspire the lender to require you to sign a new promissory note and deed of trust (mortgage). Their mortgage is still valid as a lien on the property, and if you were to default, they would file a foreclosure action against your mother's estate. They won't do anything as long as payments are current. If you were added to the deed by your mother as a joint tenant with right of survivorship (usually the case), you are now the sole owner of the property automatically. So you could sell or refinance the property, subject of course to the existing mortgage. If however the deed describes you and your mother as tenants in common, her share is part of her estate and subject to probate.