But it seems logical to conclude bike shares are not useful to you if you already have your own bike. My daughter's analysis was that more than 90% of the time the share program was more convenient even than using her own bike. THAT was my point.
I think a bike share program will work well in certain situations. One that your daughter described is definitely one of them. If you don't know where you end up going ahead of time, and/or if you take public transit which may or may not be bike-friendly, I'd definitely rent a shared bike and drop it off at a nearby "station" rather than take my own bike and keep looking for a secure place to lock it. Besides, if you decide to go straight home from your final destination, you'd have to retrieve your bike if you rode it.