At night I applied the antiinflamatory in her bump and put her back in her cage. She hated it. I think that it hurt her. After a while I put her on the floor and she went to play as usual. She was very interested in Oscar's cage, which I put on the floor while I cleaned Nana's toilet.
Yesterday morning after I woke up I found her lying outside her nest, which is very unusual for her, specially now that it's colder. I checked her. There wasn't any blood, but I thought that she wasn't able to pee because she had drunk almost all the milk that I left in a small dish in her cage the night before, but in her toilet there were only a couple of small wet spots. I took the morning off again and took her to Dr. Ozawa's clinic. Dr. Ito saw her again. He pressed gently her bladder and she peed without any problems. He taught me how to do it in case I thought that she couldn't pee. Most likely she hadn't peed at home because she hadn't woken up yet to go to her toilet. After I brought her back home she slept in her nest and ate as usual. At night, when I came back home I let her play for a while and then I applied the ointment in the bump again. She has learnt already that it hurts and hides inside her wooden home when I'm going to put her medicine.
Luckily, Luna is always glad to help me. When Nana hides I take Luna and bring her near Nana's nest. As soon as Nana smells her she comes out from her wooden home, then I put Luna back in her cage and take Nana to give her the medicine. She's obviously uncomfortable with the swelling, but it doesn't seem to hurt her (except when it's medicine time).
She's a very brave little girl.