I'm a middle aged woman and I have walked home 1.5km from the train station and walked the dog after 10pm at night. Sunshine is, however, a meeting hub and so you do need to be sensible, as Sally76 says above. I think that young male students are actually the biggest target of any street crime here (often have latest electronic devices and thugs seem to think it's okay to bash guys). I've been here 2.5yrs and never had the slightest issue. At first I was scared walking the Kororoit Creek trail but all I have ever had is friendly 'Hello's.
I have lived in Sunshine and never experienced any incidents that would make me feel u safe after dark. I always walk through areas that have good lighting and are close to main roads.