What would happen if your daughter just did a smattering of the problems to show she knew how to do them, and you explained this in an email? In a system where there is no ability grouping and no acceleration in grades 1-5, so that placement depends entirely on age, it may be rational to blow off pointless work.
This is the kind of idea that a logical rational-thinking person would have.

Unfortunately, schools don't always seem to work that way. There are three ability groups in the class, and if I send a message saying that DD only did a fifth of the problems, I risk planting the idea that either a) she has trouble with these problems and must therefore do more of them, or b) the kids in the top-level group can do
all the problems at night, and she
can't, so she doesn't belong in that group.