"Virtue"/Quality names: Faith, Felicity, Grace, Honor, Hope, Merit(t), Verity
Bird names: Falcon, Kestrel, Lark, Linnet, Raven, Robin, Wren
Landscape names: Brook(e), Dale, Glen, Innes/Inis, Meadow, River, Savannah.
"Calendar" names: Autumn, Summer, April, May, June, August, Noel
There are also subcategories within botanical - for example if you already used a tree name, you could pick a flower or vine or herb name without being too "matchy".