Critical care replacement

My little rabbit is refusing food due to her leg break (she is nibbling but nothing compared to her usual eating habits)although we are taking her to the vets tomorrow I, of course, would like to make sure she eats before then. I placed an order for some critical care but I am not sure when It will arrive so I am looking for a short term replacement. I have read in places that baby vegetable food can be okay but I am unsure and hoping someone with similar experiences can help me out? Or even someone with more rabbit knowledge?

thanks.

Grind up pellets with a bit of water until it makes a slurry, and syringe that.

I have also heard of adding a bit of canned pumpkin (real stuff not pie filling mix). Helps add some fibre to keep the gut moving.

Thanks guys will try your suggestions.