How long had she been missing? I am wondering why she would be stressed about 'strange kitties' in a house...unless she has been gone so long she forgot.

If you can take a stool sample to a vet, and mention her age, I think they could dispense a pill or two. These days, you only need one tablet most of the time.

Once the worms are gone, she'll get all the benefit from the good food she is eating, and her coat will show it.

You might want to get Omega-3 oil for cats, or ask the vet for something basic and not too expensive.

Give her a pat for me!