Simple Joysby Carter's Baby 4-Pack Fleece Pants

Is it thick or thin?

My 2 yr old is super skinny in waist. Are these smaller in waist than other brands or more standard?

Gift 4 baby due Jan24. Newborn & 0-3 months were too big for my babies. By time they fit it was hot out so do I Get newborn or 0-3 months?

Will these work with cloth diapers?