From my limited knowledge of lenses.
The lens size the best fits the "normal" view from the human eye is around 50mm.
Your daughter's zoom lens that covers 18-70mm does either side of that.
If she goes out to the 70mm end that is narrowing the image, but bringing it slight closer, so ok for landscapes but not good enough for nature photography.
As she moves towards the 18mm end this is making the picture wider and giving the impression of moving further away. This would be good for a landscape or wide angle shot.
For nature photography you need to go higher than the 80mm she has already got, so 150m, 200mm, 250mm, 300mm etc.
Obviously the higher the number the larger the object is magnified, and closer the object will appear in the lens. So a 300mm lens will magnify more than a 150mm.
You can get a "fixed" lens (so fixed at 150mm or 250mm) or you can get a zoom lens, say 70mm to 300mm.
I think the general rule is that a zoom lens is not as good a quality as a fixed lens, but of course does save you carrying around lots of lenses.
But I still stand by my original comment of NOT buying your daughter a lens but let her choose one and you pay for it.