I dont think her not sleeping during the day is the first thing that needs to get dealt with.
Are you giving her anything for the pain? If she is in pain, she wont settle down.
Since your LG is only 4 months, I would suggest calling the pharmacy and asking them what would be best, because the stuff I use are from 6 months upwards.
I am sure that once the pain is gone, she will drift off to a lovely nap.