Family car DS – also with three children?

I plan to buy a young Discovery Sport – preferably with seven seats, but this is not easy to find on reasonable terms. That’s why I also have a few 5-seaters in mind. Here I wonder, however, how the whole thing works with three children. I currently have two children (3 and 1 years), number three is in planning. So perspective would be a use of the DS with two child seats outside and a seat increase in the narrower center. The trunk would be big enough in any case.