As well as thinking about what would be aesthetically pleasing -- which of course is really up to -- and the costs of the initial work, I would suggest you think about what you need from the garden too. You say that you are a lone parent, with children, and a dog. So you probably aren't going to be able to spend a huge amount of time looking after whatever you decide to install. That's going to pretty much rule out vegetable growing, delicate plants which might need a lot of care, a lawn which really should have weekly maintenance, areas that will need regular weeding etc.
To be honest, I would probably looking at something like taking up the slabs, and the ramp, putting some kind of edging by the fence, then using weed fabric and gravel on top of that, with a stepping stone path down to the gate. I suppose given the bit of a slope you have, you might look at doing some kind of terracing before the gravel. It might stop the gravel shifting around too much, and make it look more interesting. And you can add plants in pots troughs etc as money allows, or even plant something like alpines through the gravel and the fabric. This would give some year round interest, and they are inexpensive. Pots would give you some work in terms of watering, but even if you take your eye off the ball due to family commitments and lose some of the plants it wouldn't be the end of the world, and they would be easy enough to tidy up/replace.