Give her plain boiled white rice mixed with buttermilk for a few days, that should take care of the diarrhea. Keep in mind that if it's hot where you live, birds drink more water and excretions will be watery.
It would be great if you could do you own fecals, it would save you money in the long run. I'm sure there are Youtube videos to learn how to do it. There is a BYC member here that does free testing. She is studying to be a parasitologist, she knows her stuff. Her BYC user name is Sue Gremlin. Please PM her for more information.
Your chicken friends gave you good advice about worming 3 times a year, especially if you're getting alot of rain. Worm eggs are in the soil no matter where you live, wet or dry soil, frozen tundra, Sahara desert. Birds on dry soil may require less worming as well as birds that stay on cool or cold soil, same is true for rocky or mountainous soil. Birds on warm, moist or wet soil will require frequent wormings. Chickens constantly peck the ground and pick eggs up, then excrete them. Then they become infective and are picked up again and infect the chicken. One female large roundworm lays hundreds of eggs a day onto the soil, to be picked up by your other birds. One female roundworm can literally infect a whole flock. Chickens have no resistance to worms, neither do humans. Here's an example regarding hookworms, and yes, chickens can get hookworms as well as dogs, cats etc, they are zoonotic:
https://people.com/human-interest/teen-infected-hookworms-florida/
Insects and earthworms are carriers of different type of worms eggs and chickens eat insects and then become infected.
Next time you worm your birds, alternate with different wormers besides wazine. Benzimidazoles are best; safeguard, valbazen, flubendazole, as well as other types of wormers; pyrantel pamoate and levamisole, worm out gel, and a couple others I cant think of right now.
I worm monthly and rotate with valbazen, safeguard, pyrantel pamoate and wazine.
Tossing eggs in the garbage is up to you. If you suspect you or a family member might have a reaction to the residue in the eggs, then toss them and dont give them away nor sell them.
We eat eggs after worming and I'm still here.