OMG! What a scare! I'm so glad that everything seems to be OK with her now though. It's always tricky when it comes to swallowing long strands of string like that. Cats have a tendency of finding things, no matter how good we cat proof a house
We had a similar incident with Marius, and now that I think about it, we're lucky that everything turned out ok. Aaron and I were actually on vacation and we had a pet sitter coming every other day to feed/check-up on our babies. Anyway, when we came home, I saw the pink string toy lying in a puddle on the floor (the typical barf puddle). Marius had to have swallowed it and urped it up later. I don't know if he had gotten up somewhere to get it, or if the sitter left it out because we always put that toy away when we didn't play with it for that very reason of Marius eating it. Ugh! I'm just glad that he was able to get it back up and everything was ok.

For Ritzy, I think dadcat's actions were right, because she might otherwise have choked. I would have been in full panic mode for sure!
Give Ritz a cuddle for me and tell her not to get into any more hidden string!