My experience is that pushing too hard on homework at primary can be very counter productive when it comes to secondary work.
For this reason I sympathise, and if I had my time again I would be saying to my child: no, you don't have to do it, but we have to talk about why and I'll have to talk to the teacher.
If the feedback they get on a project is very, very good then it can be a productive episode, but so often feedback is poor.
Check with the teacher whether the project is to be presented to the class for "peer assessment" because she will feel mortified and left out if so.
I think that this is a very delicate area: you don't want to give your dc the message that homework is optional, but that message does come from school sometimes because there is very little they can do to rebuke or reprimand if it's not done. Nor do you want to give them the message that mum will do it: and at the same time you don't want to force them horribly as it could have lasting effects.
The upshot is, yanbu, but I wouldn't treat it casually or as a bit of a joke. I'm sure you are more than capable of helping appropriately but this is really quite a sticky thing that might not go away.
And yes I think these projects are often a stupid waste of time when set for homework.