If the olive oil won't clear it keep her on a water only diet which you will have to administer by syringe WD. 15mL three times a day with a gentle massage after each. Hopefully it will break up and pass through. Problem is the blockage may be further down and it can take up to 4 weeks to clear, by which time they have lost half their body weight. Important they are kept moving about and not just left in a cage. We've recently successfully treated two. The blockage can start to go sour and the water controls that -letting them eat pellets makes it worse. If they are not pooing anything it can be a gizzard impaction which will be fatal. I've heard feeding them sterile live maggots will break up the impaction, but as they die in the crop I can't see that helping at all.
Have you any idea what the impaction is -grass, feathers or something else. Has she been wormed with Flubenvet recently, because the worms can be causing a blockage which has backed up to the crop. Our first case was worms with a cherry stone and the second was feathers eaten during her moult.
A BHWT vet can do a minor op to empty the crop. Done under local anaesthetic, because an inexperienced vet administering a general will kill her if she is dehydrated. Had a case of that last week on another forum.
Good luck with her. It may take a lot of time and patience and sometimes will not be successful.