It's not something I would do - you can't expect them to learn sight words or build phonemic/graphemic awareness of words when they don't have their basic sounds yet. Later in the year definitely, but not after only a few weeks of being at school! Maybe you could try listening to some jolly phonics songs with her on youtube - they are pretty catchy and have little actions that go with it. And it would be an alternative way to help her learn - if she responds well to reading eggs, then she should do well with the Jolly phonics stuff. But don't push the homework. You'll both end up resenting it. I don't know what the teacher is hoping to achieve by doing it, but I bet you're not the only parent not happy with it.