So the priest must exorcise the spirits from his daughter before she, in her possessed state, kills her own mother? Is that right?
What did the nurse/mother/wife do to these children? If it's something truly despicable then surely we want her to be punished?
Can devout people be possessed? I am not familiar with exorcisms (thankfully) but my cinematic knowledge tells me that evil spirits couldn't inhabit someone deeply religious. I could be wrong though, so apologies if I am.
At 45 words, it's a little long and I think could easily be trimmed. It's a little difficult to follow too. If it doesn't make sense on the first read through (second if you're lucky) there's a strong chance it will go no further.
Why 2 children? Why not just 1? To steal a line from The Exorcist... "There is only one". Surely only one can talk at any one time or control her? I do like the idea of two distinct personalities though... visually I'm thinking Smeagol and Gollum type scenes. We need to understand why there must be two.
What has the priest been accused and suspended for?
I would try to trim it to under 35 words and make it easier to follow. Consider things visually too... "must pull himself together" - how does this look on screen? It could be done in several seconds, minutes, hours, days, months, etc. Give him a specific thing to do that shows the audience that he's pulled himself together. Also, I think if he's not currently ready to exorcise his daughter because of whatever his personal issue is, keeping in mind that his daughter's and wife's lives are on the line, why would he not just get someone else to do it? Why MUST it be him? Easy answer, the spirits lock the house down. He has no choice.
Hope this helps in some way.