Henry Huggins is a book mainly about an 11 year old. The babysitters club girls are 13. Maybe kids could read them, but they wouldn't really even relate to the kids in the books because the characters are so much older. Just not that appropriate for 1st grade no matter how good a reader is. Anyway, probably a lot more deeper thinking could be had from reading and discussing Sylvester and the Magic Pebble and 10 other children's picture books in the time it would take to read and discuss those two books.
OP here. Well when I was 6-8 I absolutely loved babysitters club. I watched the movies, and before I could read myself I had my dad read to me. I also loved the Ramona series, Little House on the Prairie series, Secret Garden and other Francis Hogston Burnet books, the Noel Streafield "shoes" series, and Anne of Green Gables before I was old enough to "relate" to the characters as peers (and before I could read at that level, my dad read them aloud to me). I had 12 and 13 year old neighbors babysit me, older cousins, and kids from the neighborhood who were a few year older than me as playmates. I never thought that stories had to be about someone exactly like me. How weird.
I also loved the American girl series at around 6-7, which I could relate to more, but even if they are about little girls, they covered difficult topics like slavery and child labor and were about ten year olds. I got my first American girl doll at 7, and I know that my parents were reading the books to me for quite a while before that.