Hi Linda,
I'm sorry to hear about your dad. I hope that part of your visit will be going fine as well.
This is nice work here. It's been said about the trees already. I'd reduce the size, say 50%, and increase coverage indeed.
To make them look better I strongly suggest to increase the diffuse colors for the bark and the needle.
Each texture, bark or leaf, is loaded into a default-shader which is plugged into a parts-shader (most of the times).
In these default shaders the texture is applied, like bark.bmp for example. Above that you'll see the diffuse color setting, which by default = 0.5.
This means that the texture is not brightened, nor darkened by TG2.
To darken or brighten textures you can choose to do that in photoshop/GIMP/whatever, or you can do it simpler, faster and with more control in TG2.
Just increase/decrease the diffuse color number above the texture path.
So for the pines I'd start increasing the diffuse color by 50% for the needles and 25% for the bark (so from 0.5 to 0.75 and 0.5 to 0.6125).
For the needles you could also add more translucency, say a value of 0.75.
Further you could add specularity at a strength (reflectivity) of 0.3 and roughness of 0.3 for starters.
Make a croprender (not too small) and see how it looks.
Good luck with both

Cheers,
Martin