Honestly, I cannot believe folks here are still telling beginners to buy a 125 2 stroke. Not only is that bike far too tall for someone 5'4" but it is the worst beginners bike one the market. Also, any 250 will be too tall for you as well. You only have a couple smart options at your height and skill level. If a trail bike is all you need, a Honda CRF150F or Yamaha TT-R125LE. These bikes are very reliable, and will handle small jumps, but not a motocross track. If you want more performance (and price) the CRF150R Expert is the only real choice for you. This bike is a good bit faster than the other two and will handle anything you throw at it. It is great on a motocross track or on trails.