I ended up making a plum line up using Blu Tak and cotton to sort out the problem with the vase being unbalanced. Now that is something I should have done straight away, as I now can see where the problems are.
After working on the painting today I noticed I have two items kissing each other. The leaf on the wattle to the far left needs to be taken further up into the background. The other “kissing spot” is the foliage of the lavender, which needs to be taken up higher in front of the book. I will fix that up tomorrow along with the vase.