Whilst worded quite strongly, foxy baby has a point.
The option is there right now to pre book seats together which will stop any worry and reassure the customer that they will be seated together.
Having worked as both crew and also as a duty manager on the ground, these situations should really be dealt with before they step on board. Starting boarding around 30-40mins before doesn't always give you much time to ensure everyone is seated, happy and to also do your own bits and bobs too.
The option is there to them and a simple call to their pre-flight dept may put their mind at rest.
I know a few people that work for them on the ground at gatwick and are probably one the nicest bunch you could ever meet.
I have experienced working with Canadian crew and aircraft before and have also worked for a swedish company, they are no different to any other company and to be honest, the size they are at the moment, they are actually good to deal with and quite accommodating.
Give them a call or pre book your seats, will save you alot of hassle and worry.