Worms! Anyone know timeline for dewormer?

Hello!

My feral kitten was dewormed twice and then a few months later had a fecal test come back negative.  But a day after the test results, I found worms. It was really, really, disgusting.

She is now locked in the bathroom with a disposable litter box and a healthy dose of Profender. When I first gave her the medicine she didn't have an appetite and her stomach rumbled a ton.

The medicine seemed to migrate - I put it directly on the skin at the base of her skull as recommended, but the greasy spot has moved to the bottom of her left shoulder blade, so I'm concerned she didn't get proper dosing.

I gave her the dewormer about 15 hours ago.  When I gave her her breakfast, about an hour ago, she ate it happily but made gulping sounds that sounded like she was going to throw up (but did not).

I'm having trouble finding specific information. I understand cats may throw up on the dewormer, but does anyone know when I don't have to worry about her puking up worms anymore? So she can get out of the bathroom.  What's the timeline for this working?  And do I need to be worried about the medicine moving?

Thanks!

Are you sure the worms are round worms? Did the vet listen to her chest to ensure they're not lung worm? Profender won't treat lung worm.

I've never used Profender. I looked it up, and it says it's just a one-time use product, but it would seem something isn't working right. We've always used Revolution, even though it needs to be used more than once, as it doesn't kill the eggs, just the adult worms. The life cycle of the worms is such that if you're using a product that only kills adults and larvae, but not eggs, it needs to be given every three weeks. Most vets have you apply it just twice, but we always give it for three doses, each three weeks apart, because we've had the round worm battles before.

Sorry, I should have specified.  The first two dewormers were oral.  This is the first time she's on Profender, and it's not supposed to need another dose because it stays in the system for at least a month.  The vet said her breathing was normal; and the other cat had roundworm eggs in his stool.  Therefore we're pretty confident it's roundworms.

Oh, OK. Well then I'd consider giving another round after a month, just to be sure. But that's me, and we battled drontal-resistant round-worm back in the day when there were no topicals.