So yeah playing with kayle jungle is all about farming until level 6 or sometimes even 11. All advice I can give you is to stay away from invading and dueling the enemy jungler. Ganking pre level 6 is possible but a little weak... if you do gank just focus on hitting your Q for the slow and using your W on your ally so he can do the damage for you then use E as late as possible to get the maximum effect out of it.
I did get my lvl 7 on kayle only by playing kayle jungle so that is the only credibility of my skill with her that I can give you.
Also good luck