Sentence 1: Jane had a very sick dog. 
 Sentence 3: So that he still felt young, Jane used to walk her dog in a pram 
 Sentence 4:  This would look strange to the public 
 Sentence 5:  Jane didn't care as she knew she was making him feel better 
 Option 1: But it got better. 
 Option 2: Her dog was old and couldn't run anymore.