Ganredhel

From the OblivioWiki – your guide to everything Oblivion

Ganredhel is a journeyman acrobatics trainer who lives in southeast Cheydinhal across the plaza from the Great Chapel of Arkay. She seems to prefer dogs to people, and is constantly surrounded by a small pack. She will begin training early, shortly after 4:00 a.m., and continue until late into the evening.

If you enter her house looking for training, her dogs will attack, but she would still train you while her dogs are in the midst of attacking you. So get in, train and get out. Or you can wait outside until she comes out. Not sure what happens if you kill the dogs.