I suspect, but I have no way of knowing, if it is a nun or not who writes Ask Sister Mary Martha, but it apparently is someone with a fairly deep knowledge of Catholic doctrine and a great sense of humor. The blog's tagline: "Life is tough. Nuns are tougher" says it all, as this "tough nun" serves up information and advice about all manner of problems, saints and questions about Catholic doctrine.
Some of my favorite posts are about how she recommends different patron saints for different needs, from Blessed Andre of Montreal for protection of property, to the patron saints of twins.
She answers a funny but not unusual question about going to confession here.
Along with the humor, there's lots of good information on this site about saints, Catholic history and Catholic doctrine.