TBH I too would be a bit scpetical about her saying that "all" the work is too easy and boring. ASk your DD for more specifics.
Just thinking of some typical work as examples:
Art - this can't be too "easy" as they will have a lot of free fllow stuff, so it is hard/easy as the child want it to be.
Writing - one of the biggestproblems here is that the instructiun might be to write 3 sentences about xxxx. Now if she just writes 3 sentences, yes it will be too easy. But what is to stop her from writing more, and in more detail. The teacher could ask her to add ore details, more descriptive words, look at punctuation, etc, and to illustrate her work carefully. Sometimes the extension could be to type it on the computer.
IT - there are so many ways this cn be made more challenging by looking at all the options. Fpr example, I have shown DD how to start doing mini presentations on PowerPoint, hpw to present her wor in different forms using word, DTP and Power Point, how to incorporate images and manipulate them, how to use google, etc.
Geography/History/RE/etc. - not sure what the topic is but again a lot of this is written too - so adding more details. It is unlikely she will know all the subject matter for subjects like these at this point surely? If she has then the teacher needs to get her some more materials to look at and explore further, based on same topic but asking your DD to consider them in a nother way.
These are just some very smple things I see happening a lot in DD's classrooms, and way more.