Her IB kindergarten doesn't do formal reading. Her cousins her age are reading full sentences

Cousins reading early don't prove much. At that age our daughter could recite three whole books from memory, and the elders were sure she was reading 😊 Ask the cousins to read something they haven't seen before.

I teach at the other end of IB, but I see the results of both kinds of start. Children who were read to a lot and enjoyed it tend to catch up quickly once formal reading begins. The ones pushed early sometimes read well and dislike it. If she enjoys sounding out words, a few minutes of play at home won't hurt. I wouldn't turn it into a lesson.

Been there, my daughter was IB from the start. Ba asked the same 'wasting a year' question, word for word. She caught up by the middle of grade 1 and now Ba brags about her reading. The elders will find something new by next Diwali, trust me.

When people say 'it evens out by class 2', there's usually an unstated condition: the child is read to every day at home. If that already happens in your house, I'd trust the pace. If evenings are busy and books are rare, a short daily reading habit matters more than which method the school uses.

is she staying in ib for primary? if she moves to cbse for class 1, the books assume she can read. that's the only reason i'd start at home

Haan, family functions are the worst for this. My daughter was the 'late reader' at every one in her UKG year, and now she reads past lights-out and argues about it. Ten minutes of a fun book at bedtime was all we did 😊