City bikes-- frame sizing for smaller cyclists
I helped a friend having a similar issue long time ago (she was 154cm ... I think it is similar height to yours, right?).

What we found was that a 17" frame would be okayish regarding leg's length, but a bit of a stretch regarding the torso/back, because the handlebar was too much forward.
However, for cycling stretches of 20-30 minutes this may be ok and you may still have a relatively simple albeit unconventional solution: reverting the stem (the metal piece used to attach the handlebar to the fork) to point backwards  

In our case, the solution was to buy a 26" bicycle. 
Sometimes these bicycles are advertised as "young adults bike" but they are completely adequate for your declared purposes.