Economical And Efficient Non Geared Vehicle

Hi Guys!!!

I am planning to purchase a two wheeler non geared vehicle for my sister who will be going to college from coming April...

I have absolutely no knowledge about the vehicles and about their specifications...
I am looking for a two wheeler that is easy to handle and can be easily parked
It is needless to mention that i should be economical in maintenance and should give a decent mileage as well...

Please suggest me a two wheeler that will suit my needs