Not really a safety question but more a kids and cars question.
DH and I differ in what we like. He likes cloth for comfort because it gets hot here (so do I in that regards) but I prefer leather for ease of cleaning split liquids/etc.
Does the vehicle in question offer cooled seats? We've got AC in our leather seats and it rocks. No more legs sticking to the leather and if the kids are too cold, you can make the vehicle temp less cool but turn on your cooled seat to keep you cooler than the kids. One of those features that I thought was useless before I had it, but now I think rocks!
We've got remote start as well that if you start the vehicle with it prior to getting in, not only will it adjust the inside vehicle temp, but it will heat/cool your seats depending on season so when you get in and sit down your seat isn't too cold or hot for you.
I should also add this will be our recreational vehicle (take it to the beach to surf, mountains to snowboard, etc). So beyond kids, we have that to consider.
I hated hot leather on sandy beach days. With sunscreen and/or bug spray on me and shorts or suits, we'd always stick to the damn seats. Although the cooled seats have pretty much resolved that (see? cooled seats rock!).
We had a leather option for our vehicle with cloth but the vehicle didn't offer heated rear seats (just front) so my daughter said, "let's get the cloth so I don't torture my friends with freezing leather seats in the winter!" (her and I share the driving of that vehicle). She's had experience being a rear passenger in the wintertime with leather seats that weren't heated and she always complained how freezing it was. Our next vehicle after that had heated rear leather seats and same with this vehicle.
Neither one of them seemed to be any harder to clean or maintain, or feel colder or hotter in summer, honestly (tinted windows are an absolute must for me, that probably helps...)
We've got tinted windows in our leather vehicle and less tinted in our cloth vehicle. I drive both and I do find the cloth cooler overall *if* I don't have the AC seats turned on for the leather.