Cracking lumps of emulsion on lining paper- sand off?

[MPEJ]

I've been painstakingly decorating our dining room for two weekends now. Having carefully laid lining paper adjacent all the way round I added a light coating of watered down eggshell emulsion with a roller yesterday having left the edges well alone.
I come in today to find my wife helpfully cutting in along the edges (no masking on the edges but that's another nightmare!) anyway she's laid it on light plaster. It's got brush streaks so deep there like troughs and there are lumps that are now cracking and flaking. It looks like bloody poster paint.
Can I sand this back? Any tips to save my beautiful project are appreciated.

 

[Bosswhite]

I would tell her what a good job she has done and how very helpful she has been, !!

It will save your marriage !