Edelweiss, Lavender and Mountain Lilly had much higher stats than all other event girls and thus are worth blooming, other than that ignore event girls and focus on Gatcha girls.

As a general rule the older a gatcha girl is (The longest ones to be in the game not character age) the weaker her stats will be tho Peach is an exception. The game stats in general seem to have been creeping up so most girls that are released now have better or slightly better stats then those that came before.

To be honest tho it's not going to matter that much, just level and evolve all of your girls once even if you do not then max them to 70. That was you can look at the evolution button and see only bloomable girls, from there choose the ones you like and if you are really concerned about whale ship.... bloom the girls with the most equipment slots.

A lvl 80 event girl with 4/4 equipment at max level will still have the same or better stats than a gatcha girl at 1/4 equipment at lvl 80.