First, I'm sorry to read this about your sister. I was coming back to this horary many times. I was waiting a positive update or something similar.
Horary Medical Astrology is a bit different to what we have used to practice with other questions. The subject of traditional medical astrology ( I'm practice it) is like a 10 volumed encyclopedia and complete different to the west medicine. Anyway, I would like to judge it.
Your sister is signified by Venus. Venus is a cold and moist planet being on a hot a dry sign. There is a humoral imbalance here. But we already know that she's sick. The planet of the disease is the planet that rules the planet of the body. In your sister's case though, Venus is in her domicile. This essentially dignified Venus doesn't mean she's OK. If there is a humoural imbalance like we saw, then she's ill.
There are three planets here harming Venus. Saturn, Jupiter and the Moon. Saturn is more prominent though because it is right on an angle, making its presence strong.
According to a traditional text " ....Saturn is cold and dry in the 4th degree ". This is not good because in the 4th degree signifies that the illness is serious. The problem here is there is too much coldness and dryness that disturbed her humoral balance. Cold and dry is the quality that is limiting the life force and makes no connections. This could manifest in a variety of many symptoms. When the quality of the cold and dry quality is excessive, then we need to light and moist things up. The air element is needed because we want to take out the this coldness and dryness. This could be either an "air" diet (foods corresponded to the air element) or a change in attidute and daily round.
The Moon points to this direction as well. Saturn is the cause of the disease. The Moon has separated from Saturn. Saturn an also cold and dry planet. Saturn is the last planet out there, so it rules limits and blockages. It signifies the immune system because it is the last wall again the world out there. Maybe there is something that limits or blocks in a way ? I don't know. It could be. Maybe a depressive attitude that manifasted into headaches ?
The treatment the doctor proposed (L10) has no effect on Venus. Probably a moderate effection because Mars is about to change sign and enter Venus' triplicity. That treatment isn't the solution. Mars is ruled by Saturn, the disease has power over the treatiment.
I don't think your sisters condition will go better. This is an essentially huge Venus that will keep that for a long time. So her condition now is as good it gets.
I really hope for the best !