An Upper Dublin woman who admitted causing cuts, brusies, welts and burns on her adoptive daughter's body is doing jail time.   A Montgomery County judge Friday gave 53-year-old Theresa McNulty at least eight months in county prison.   The abuse happened over a period of several months when the little girl from Russia was between one-and-a-half and three years old.   McNulty stood stone faced as the judge called the case horrific and sad.