A lot of the displays are raised up and even with a step-stool (on loan from the entrance desk) we had to lift Charlotte up for a few things (she is 1m, displays are 1.4m). There was quite a bit of history we could teach Charlotte about, how buses have changed, and trains, how we get our water out of taps instead of a man with a horse and cart. But I think being a girl some of the train things were a bit lost on her.
Pendon does offer a good value hour or so hour slowly wondering around the displays, its all indoors and run by volunteers so great for damp days and something for all the family. There is one set of stairs if taking a pushchair, a small tea room, didn't notice any babychanging facilites in the toilets.