Broody hen

I have read everything I can find about this, various ways of stopping a hen from being broody, etc.  I have a Light Sussex, one of four varied hens (no cockerel - suburban garden).  She has been broody for about a week now, for the second time.  Last time I just kept taking her down and she complained a bit but stopped after a few days.  Now I am taking out the eggs (not hers I think, she is keeping the others' eggs warm) and giving her some food and water, etc. and she just goes back up to the communal nest box.  Will it do her any harm to carry on like this until she stops?  The others aren't bothering her and I don't mind as long as she is ok.  Otherwise I will resort to more drastic measures.

You cant stop them going broody but there are several ways to deal with it.
1) let them have fertile eggs,
2) keep removing the eggs so she is sitting on nothing - can take weeks,
3) keep removing her from the nest box - again can take weeks,
4) put her in a cage with food and water - can take between 1 and 7 days,
5) dunk her bum in a bucket of cold water - this lowers her body temperature - not tried this method but she may need several dunkings (just make sure she dries off though).
So far I have tried methods 1 and 4 - much prefer method 1 though