Chinchilla not walking in a straight line

Hi, I've had my two chinchillas for 2 months now and they are 5 months old. Before I start I will be taking my chinchilla to the vets tomorrow I just want some advice in the mean time or to know if any of you have experienced this so I'm a prepared for what might happen tomorrow and if I might lose my chin. She is a female and recently when I let her out of the cage after a while she will fall on to her side and is unable to walk properly she panicked and rushed to her sand bath but stumbles about everywhere and falls to her left side continually while trying to walk, when I pick her up to put her in her bed she is limp and does squirm which she usually does as she prefers to just be running around. After about 15 minutes she is back running around again, this has happened about 6 times now. Is it a mini stroke? Or just something as a simple as a sprain? Thank you for any replies I get and like I said I will be taking her to the vets tomorrow I just want to know if I should be prepared for the worst. Thanks