Originally Posted by VortexMagus

Lavendar? Dipladenia? Edelweiss?

I always thought these girls were fairly subpar due to lack of passive damage increase on their abilities. Their stats are pretty good but why do you value speed and solar flare boosts and pest control nodes over, say, +10% damage and all that jazz?

Ignore Whirlwind and Spider Web nodes, as well as Speed buffs, are good for controlling squad arrival, which on many maps means 2* or 3*. Also, high speed affects auto-run time significantly if you like to be tabbed out doing something else for a few minutes (look at a 400 speed squad's movement rate and a 700 and you'll understand)

Heal on Pest node: Just look at 12-5 in particular, but many maps have lots of pest nodes and the damage from fights and small pests add up. This should be self-explanatory.

Lavender isn't for the Solar Blast, it's the Spring of Recovery (granted, it's benefit lacks consistency based on where the springs end up, but accumulated damage, particularly with the increasingly strong enemies, adds up).

Also, Lavender and Edelweiss (along with Mountain Lily) are the only event girls whose stats and abilities aren't slightly nerfed compared to their gacha counterparts. Event girls are also reliably able to come with max skill and equip slots, something their gacha counterparts can't claim.

Attack buffs are nice, but they're also super-common. These 3 come with fairly rare abilities and decent stats. Also, extra healing means your girls live longer to make use of other girls' Attack buffs

Props to EAB for his rather nice explanation of most of the girls on that list.