Do you think they will grow to be a bout the same power level as him?
In my opinion? I think they'll be on the same level.
I don't take the Kawaki scene too literally. I think the real reason Mitsuki and Sarada are not found there with him is because Boruto shooed them away, either because he's a former friend or because they were once in the same division or something like that. So now Boruto has to take him on because he has a sense of justice and wants to execute Kawaki himself or because they have an unresolved rivalry which is accompanied by set of beliefs like Naruto and Sasuke at VOTE 2.
So I think while Boruto is facing Kawaki, Mitsuki and Sarada are taking on other Kara members, or protecting civilians. Either the former or the latter, but both are what I imagine they would be doing.