If she is not sitting on the eggs I don't think it would be classified as "broody". I would personally move the eggs to where she is sitting to see if she moves away from them as a test.
I would wonder if she is egg bound. That can be serious.
I would let her spend time floating in a tub of lukewarm water, no soap, and boost her calcium intake for a few days. She may be trying to pass a stuck egg.
Half a Tums, or a crushed 200 mg calcium citrate tablet in some treats like thawed peas is what I'd try, then cut back to half that amount for a few more days.
Ducks can get infections in their oviducts as well.
Is she pumping her tail? I mean the tail goes from normal position downward, repeatedly.