Best thing I can manage is 2 stars on 3rdmap, Im still way too weak

But I try again next week maybe by then I can manage the 3 stars or maybe 1 star the 4th map

PS: I manage to get plat Valk thetis whos stats at lvl10 are similar to my lvl30 elaine and my kerry is still lvl1, so which of the valks should I lvl up?

Also got an extra copy of Iris and Bernice, should I wait till I can CC the copies and feed em to my main Iris and Bernice?