Smelly Poo Persists - Is It The Tapeworms?

I adopted my girl two weeks ago, and her poo smell seems to just keep getting worse, to the point where I can smell it if she's used the litter box in the other room. 

She was diagnosed with tapeworms at the vet Tuesday, and received a deworming pill for it. What I'm wondering is, could it be the tapeworms causing the smell?

I know her diet might be the cause, as well. I have her on Purina One Indoor Advantage dry food, and she's been eating the Fancy Feast canned pate styles in chicken and turkey at night. I am switching her wet foods starting tonight, and bought three-different grain free brands last night (Authority, Simply Nourish, and Good Natured) to try. I also am considering slowly transitioning her over to the Good Natured dry as well, after reading the good reviews on here.

What do you think - is it the tapeworm, or is her diet the issue?

Tapeworms and the medicine could definitely be the issue. 

I'd give her about two weeks after she's gotten the all clear on the tapeworms before getting really aggressive with the food options. Please keep in mind, especially with dry, to change food gradually over at least a week and give her system time to adjust between changes. Otherwise you might end up missing the thing that helps or making the problem worse.