Here's what our pickapro garden landscapers suggested...
Solution 1: Synthetic Grass
Dogs will dig, and there's probably no way around that. I would probably suggest synthetic grass. It will be clean and neat and it will also be softer underfoot than pebbles. For big dogs such as labradors that tend to suffer from joint problems, that can be important. When it first came out synthetic grass looked very artificial. Now you can get grass that comes in 2 or 3 tones and it's remarkably realistic. I'd suggest that Geraldine doesn't go for the most expensive grass It doesn't always look as realistic in an Irish context - it's nearly too luxurious.
Solution 2: Resin Bound Surface Paving
There's a few options that the dog wouldn't be able to scratch up. One very low maintenance option is resin bound surface paving. This gives the the appearance of loose pebbles without the maintenance issues. It comes in 110 different blends of natural stone. Geraldine could combine it with some intricate paving patterns or edging to make the whole area look really well. Other options are synthetic grass or a fused rubber mulch, similar to what you might see in a playground.