Normal or concerning dog behavior?

So I found a what I think is a stray dog, Monday around 5pm. Writing this it it currently Wednesday at 6pm. The dog is really sweet and seems well behaved other than being weird indoors. I think maybe she’s was never let inside if anyone did own her. Anyways she was covered in matted fur and I shaved her the best I could. She’s had two baths and pulled 3 tics off her. Everything is great except she hasn’t pooped yet. She peed on the leash for me but that’s it. She ate Monday and Tuesday but last night and this morning skipped out on food. She doesn’t seem stressed to me but I’m obviously no dog expect and am increasingly getting nervous because I cannot afford vet bills for this animal. I was just planning on trying to rehome her if she had no owner.