I didn't grow NHS yet, have a pack though.
I think the lemony/citrusy terps come from the Sativas used in both the Haze and the Skunk.
Probably the Colombian or the Mexican would be my guess.
Anyway, anything that builds on these should have the potential at least to show citruy terps.
On the widow side of things I cannot confirm but it wouldn't surprise me as I assume the same or similar landrace sativas are part of the mullumbimby madness.
In terms of mostly sweet or fruity aromas: There is always some variety and I am recently suspecting that the personal growers environment, soil mix, nutes etc. play a significant roles in what terps show.
Across 2 grows with wide varieties of strains from various seedbanks, I have noticed that I seem to run into 2 distinct phenos again and again, across multiple strains.
I keep getting that undesirable "camphor" smell that is really unpleasant and stinky but not in a good way.
And then I get this fruity, bubblegummy, lemony, citrusy pheno.
I was really down on myself for not being able to save a clone of the MKS that had this pheno. But the following grow I ran into eerily similar aromas (not 100% the same but very close) in both a World of Seeds Colombian Gold and a Mango Haze IBL.
In between there were other phenos, some grapefruity for example, some super low odor (c99) but these two, camphor and sweet/citrusy keep showing up for me.
I am afraid nobody will be able to give you a sure fire strain that will give you lemon terps 100%. Maybe some feminized strains ...
Otherwise I would suggest to look for strains that include Skunk and Haze as both strains use certain landrace sativas that I believe are what passed on these terps. And both Skunk and Haze have been used in a whole lot of crosses, most of which have a report or another floating around the web where citrusy/lemon terps are mentioned.
After that it is just pheno hunting like everyone else and isolating a lemony specimen.
But I have only flowered about 20 plants so far and I have come across lemony terps several times. It shouldn't be too hard to find what you are looking for.
Finding an excellent specimen with dominating lemon aromas could be harder of course but that's part of the fun isn't it?
Stay frosty and all the best