It's them midichlorians my nikka.
If you're force sensitive you're gonna apply it to whatever you do and if you put someone in a hostile environment they will probably pick up some fighting/survival skills.
As for her beating Kylo, the LAST thing wants to do is hurt/kill her in anyway, he was pulling his punches.
So you are a believer that she was trained and Kylo knows her? Which would help me accept certain events
However, successfully applying instinctive fighting and survival skills against regular civilians, I would understand, but not against a trained person of the force, especially with a lightsaber. Kylo was getting tagged up and bruised for a person who was pulling punches
Kylo not trying to kill her would make sense if we followed the narrative that he knows her. But then why in the TFA did he cop pleas to Snoke about her being untrained but being very sensitive to the force? He could've said to Snoke that he seen her as a youth and was probably trained by Luke
Lucas is a bytch-azz nikka that could've pulled off an epic movie twist, but instead chose to waste all that screen time and character buildup. smh