Rescued a soi dog and Thor was not happy about it

Last weekend I found a dog on the soi near Bang Sue station. She was sitting next to a food stall with a broken leg wrapped in old plastic. Nobody wanted to touch her. I took her to a vet nearby, they fixed the leg and she stayed two nights in the clinic. I named her Nam, nothing special. Now Nam is at my place, and Thor (our French Bulldog, 4 years) has decided she is his new enemy. He growls and blocks the doorway, he does not even let her eat near him. I thought he would be happy to have a friend, but no. He wants the couch and the blanket and both of us, I think. I am giving them time. I keep them separated at night with the baby gate, and in the day I walk them one at a time. Nam has a funny habit of rolling on her back when Thor comes near, like she is saying sorry. Thor just looks away. If you have adopted a soi dog with an older dog at home, how long did it take? I need to know it gets better. Right now the house sounds like a very loud argument.