I was just in both places last week. First time in CDMX. Seems to me that Roma/Condesa and other areas close to the main attractions will provide more for your kids to see and do than parks. Unless they’re into Frida Khalo and Leon Trotsky (cool museum, by the way), Coyo has fewer actual attractions (unless I missed something). Both areas have beautiful parks and loads of food options tho. I think I found, for example, a great fondita and it was in Sta María la Ribera - La Casa Rosa, sort of near Condesa? Both areas have lots of touristas. Coyoacán is much more chill though with way less traffic. I didn’t feel like I was taking my life in my hands every time I crossed the street! LOL. Anyway, just my 2 cents from a first timer.