Julia is one of the nicest people you will meet! She has a lovely place that is within 10km from just about everywhere important, she is a fantastic host that will let you do your own thing but is willing to talk if you are up for that as well. I was at a music festival, and she was totally fine with me coming back (quietly) at 3am. I would definitely stay with her again if I stop in Madrid again. Also, her English is much better than she gives herself credit for.