They can appear to be COMPLETELY normal and still be carrying quite a heavy parasite load. Adult dogs aren't as outwardly affected by worms as puppies are. Puppies tend to have big, round bellies when they have worms, adult dogs don't. They pick them up sniffing around outside, stepping in places where infected dogs have defecated and have dropped eggs and worm cysts, and then licking their paws. Even one flea, if it is a tapeworm host and is ingested by an animal, can cause a tapeworm.
It's a good idea to have a fecal done on your dog once a year just to make sure they're clear of worms.
Ghilly
Yes, she could. The best - and fastest - way to confirm that is to bring a fresh stool sample to your vet with the dog. Some worms are so tiny they aren't visible except under a microscope.
Why does you daughter think the dog has worms? From what you describe, it doesn't sound likely, but it's always possible. Also, if a dog is on regular heartworm preventive meds that lowers the possibility of a dog having many kinds of intestinal worms.
I rescued a puppy in a deserted rural area in 1990. He was skin and bones and had every parasite a dog could have except for heartworms. Our vet wormed him 3 times and we thought that problem was finally over. When he was about 3 months old, we were still battling severe mange, so in desperation the vet tried the only thing left to him other than mitaban dips: a shot of heartworm treatment. I didn't know it was arsenic based, and within 20 minutes my poor dog was vomiting. Then the diarrhea started. Over the next 24 hours he was completely emptied and the last few BMs were nothing but worms.
That shot didn't help the mange, but he never EVER had worms again in his nearly 14 years with us. He had no symptoms of anything wrong, nothing in his stools, zip, zero, nada.
So - yes, go ahead and have your dog checked by your vet. It's always better to be safe than sorry. :-)