jailbreaking a locked iphone5s
I have just received a phone call from a very distressed friend of mine, she was bought a Iphone5s as a prersent by a now ex boyfriend, he paid for the handset outright and gave it to her, she had a little baby with him who is currently very unwell and the piece of work has found it funny to get the phone blocked because he still has the box , imei number etc at his house to do so, so basically she is left with no phone and no way of contacting anyone.
My question is this: is it possible to jailbreak a locked Iphone 5s? I have done a small amount of research and have come across Evasions new software that supposedly is just what I am looking for, would this be ok to use?
Speedy answers would be appreciated thanks alot guys
I am long term mac user very familiar with the hard/software