The reservation is one thing and the ticket you need to create in the app is something else. Even when you have a reservation you need to create a trip in the app and create a ticket with a QR code. This means that your husband shows his ticket on his phone and your can show the reservations for the 4 of you.

Thanks for this so, all a but confusing. Am I right in thinking I should only add 3 passes to my device for me and my two daughters and he adds his pass to the app on his own device?

Yes, if you know that you will be travelling together with your daughters all the time that would be fine.

Just to add there that if you anticipate that your group would split up at some point in the trip, we advise that you add each traveler's pass on their own device for the sake of convenience. If all passes have already been added to a single device, you can simply contact customer service so that we can disconnect the relevant pass for you. You can make reservations separately by simply ticking which travel you wish to make a reservation for.