Hi
Could you post her usual EAS times please?
It seems to me that as she has enjoyed solids up to this point there is likely something else going on rather than just not liking the food. You say she is not ill or teething but might she be tired for instance?
Many LOs will eat more earlier in the day and may take a larger portion of their calories in the morning and afternoon hours rather than the evening. In particular the dinner time meal may be coming a bit too late for her. It could be a simple case of tweaking her EASY, moving dinner earlier, or offering lunch instead of dinner (or as well as dinner as she is 9 months).
It may also be that she would like to have more control over her food - are you offering finger foods or a pre-loaded spoon/fork for her to self feed for example? The tantrums may be related to wanting to do it for herself.
There's no problem with offering an egg every day although personally I'd rather see a range of foods being offered rather than limiting her diet down to one or two foods she appears to have a preference for.
WRT weaning the DF. This does not need to be linked to how many solid meals she is taking in the day. You are offering both milk and solids in the day and she has the option to take them. She either has the ability to go through the night without a feed or she doesn't. She will increase her calorie intake in the day hours to make up for the lost DF (she may not immediately but will after a few days) and if she is unable to then she will wake for a feed. If this happens you can always reintroduce the DF but my guess is you won't need to.
If she throws a tantrum at her meal, throws it on the floor or turns her face away, I would say something like "OK, looks like you've finished, lets clean up" wipe her down and take her out of her high chair, move on to another activity (or have a cuddle if she is still upset). If she indicates she wants to return to the food I would give her that chance, before putting her in her high chair tell her something like "Oh, so you are hungry then. Let's enjoy our meal together. If you shout I'll think you are finished." I would only let her return to the food once at each meal though, this doesn't need to turn into game of in the high chair out of the high chair.
You ask if you should offer something else - at each meal I would offer a couple of different things out on her plate or tray from the start of the meal and that's it. I wouldn't start looking in the fridge for something different and then something else and so on.
Do you eat your meal with her at the same time? This can have quite an effect on what and how much LOs eat too.
Hope there are a few ideas there to get started.
Please do post your EASY and any further questions.