They could be considered kids bikes but we had got down to the choice of this or a bmx, the one we have (Doris) had been supplied new with a five speed but had been converted to a sturmey, the tubing is certainly up to the job of carrying a larger framed adult and the wheels are not too far from a raleigh twenty's in construction and are 36 spoke so well built. When my beloved is seated on it, it is all in proportion and she finds the fit to be well suited. Like I say it is a stop gap to a more modern solution but has got her riding voluntarily, I think it will have more legs with some modern 24"s and the option of a 5 speed, some of these being used by the downhill off road types so should also be up to the job and there are road tyres available if you look hard enough. Like I say I have changed many components on it to give it a more grown up feel. We are looking at cyclo cross type double levers for it too as the eighties style safety levers I have fitted are not great as she cannot get a good grip on the drop lever with her more petite hands. I am not saying it is a solution that will suit everyone of a petite stature or be an ideal c2c bike but for the local journeys and out of town jaunts it is well up to the measure and is growing with her confidence and my mods.It also has shorter cranks a lower bottom bracket height which also help with the fit too and is well worth looking out for as she can reach the floor without too much of a compromised riding position It has also saved a good bit of cash doing it this way as it has taken a few bikes to find what she actually wanted, at first it was sit up and beg with a basket or nothing. We have stumbled upon a saddle that now will be with her until it wears out which is also good.
again good luck and keep looking!
Gaz