Your height: 4'11" to 5'3" (150 to 161cm) approximatly (?).
Frame size = 20in/51cm
Comments:
Hybrid Bikes: they are a good compromise between performance, comfort and sturdiness. Good for the city and bike touring, rather light weight and narrow tires, many gears to go anywhere.
10 speed: good to go just about everywhere except very steep hills. The range of different ratios are more than enough for most people. There are 2 front chain rings and 5 rear gears. - Derailleur:
Tires 27 x 1 1/4: narrow tires with small thread or slick, for speed on asphalt, very common on vintage road bikes.