Your height: 5'1" to 5'6" (154 to 167cm) approximatly (?).
Frame size = 19.75in/50.5cm
Comments:
Simple bicycle with large and slick tires good for city pavement
Mountain Bikes: they are sturdy and designed to go everywhere including off-road. Good for rough riding. In general heavy and with deep thread tires slow on paved roads. Not good city bikes unless narrower and slick tires are installed.
12 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 6 rear gears. - Derailleur: Tourney Shimano
Tires 26 x 1.75: medium width tires with small thread, for comfort on asphalt and occasional off-road.