Thats a good workout
Your sister boxed? ...thats cool ...she knows how to train? ...nice ...she'll help ya a lot if she knows what she's doing ...
I got a simple Forearms exercise for ya
Take a simple Wood broomstick drill a hole in the middle
Take a rope tie it ...one end tie through the hole... the other end tie to a weight ...start with whatever weight your comfortable with
Grab both end of stick... hold it straight out from your chest ...both arms straight out
Now slowly wind it up .....and slowly back down...your forearms will burn
Also get a cheap hand squeeze
With strong forearms and hands in a street situation you can overpower most if ya had to ...