My rabbit has a lump near her anus, eating fine. Urgent vet visit?

Lumps and bump can certainly be scary, especially since we usually don't have any idea what they are. As long as it is not effective Poppy's ability to urinate and defecate, and as long as she is eating / drinking / having a good energy level, there is not absolute rush to have her seen. However, I would definitely get her to the vet to have that area examined as soon as it is financially feasible to do so. It is in an area of the body where if the size increases, the mass could certain become problematic. It is best to deal with it sooner than later. If the area starts to grown in size by even 10%, I would not wait until the insurance kicks in and just get her somewhere to be examined. While I realize this isn't ideal, rabbits are very sensitive to changes in their health and have the ability to crash quickly if things are not hastily dealt with. If you have any others concerns, don't hesitate to contact me. Hope this helps!