I have lived for about 11 years in Noble Park. I myself never had any issue. But in general ,area has improved a lot over the years in all aspects. I have lived on Buckley st for 5 years before buying my own property around Yarraman and bloomfield which I find pretty safe and quiet. In any suburb if you gonna hang around train station at late night you will probably find yourself in difficult situations.
I am a mid-30s female and have lived in Noble Park for about a year. I do feel safe walking the streets. I do keep to main streets when walking home from the train station at night, but I would do that anyway, wherever I would live. I'm not sure what the area south of the railway line is like in terms of feeling safe day-to-day - I live on the north side and I really love living there and I feel safe.