Those two women are Eliza Danvers and Alura, alias Helen Slater and Erica Durance respectively.
Also, Arrow's Katrina Law is slated to be there from June 6-9.
From the Superman Celebration Facebook
Who runs the world? #girls These unbelievably talented women will be here for the 41st Annual Superman Celebration! #msc2019 #supermancelebration2019 #helenslater #supergirl #ericadurance #loislane #katrinalaw #arrow