Fixating on something minor. B got to drive a JCB once out on his brother's wood chopping business in the US (where you don't need loads of health and safety checks and licenses and so on to be allowed into the cab) and he said it was pretty easy. I imagine basic usage of the one we see Abby in might not be too hard to acquire especially, as you say, through the zoo work - though I've no idea what the certification requirements may be. I think you can hire the little ones domestically though so that suggests its not too difficult to get the right paperwork if you need it.

More generally I think this must be one of Abby's best episodes for showing her being mature and competent and getting on with things. Not being put in the roll of babysitting Connor probably does her character a lot of favours at this stage.