Toy Story Collection Jessie doll voicebox doesn't work ;_;

I have a Toy Story Collection Jessie doll and she’s in great condition, except her voicebox doesn’t work and I don’t know what could be the problem.

Her pullstring still pulls although it doesn’t retract as strongly as it probably should. I tried replacing the battery inside with a brand new one from the store, but she still doesn’t work.

What can I do to fix her? What might be the problem?? I’m not a technician or anything, and I want to get her back to normal so I can hear her, because she’s my favorite character.