Im 5'3" just upgraded from a CBR250R to the Ninja650R. Had it about a week - totally love it. I was concerned about the heavy weight and it being a little taller.
Its only about .5 inch taller - my feet are still at a comfortable level for me. Its definitely heavier but I am totally surprised in a good way offering stability. The power is a lot more for certain but the ride is smooth and stable.
I totally recommend it. See if you can find a dealer that will let you test ride, or if the person selling will let you. Once I test rode the 650, I was sold.
and... I totally loved my CBR250R - best starter bike ever - if my husband and I weren't planning to do weekend trips, I'd have kept it for the daily ride in a heartbeat.