Who else can be an ally for the GoodKaneDom, we will find out when we see all 3 parts of ep8, in which we will have to make the final decision on which faction we join. And by factions we don't necessarily mean just the Karlsson sisters (as sponsors and allies). It could very well be mixed factions of people who are technically adversaries (e.g. Karlsson<-->DeKocks<-->New Paris).
As for Karlsson sisters you can trust...Well that depends on your personal preference. Personally, I have confidence in Veronica because we have a pretty deep bond with her that means more to her than it might seem at first glance, and the origins of that come from their childhood.
Good Dominique can also be a trusted ally for good Kane. It has to be said that both Dominique and Veronica have a high
flexibility rating, which means that Kane will be able to change their worldview in the right direction, making them more human and kind.
Our most important ally among the Karlsson sisters, our lovely Olivia, who on the GoodDom route really cares about Kane and even Seth, I won't consider, because:
a) it's already obvious
b) we can influence her decisions to a large extent.
So just proceeding from the fact that we have a powerful force that can have our back and support us, but who quite possibly in the future, when Kane is no longer a fake prisoner slave (i.e. gets rank M and above), will very likely need our help.
When it comes to current allies (but not factions), it is without a doubt Elena,
the real-life mother of Olivia. What makes Elena special is that in addition to being one of the founding members of the Karlsson Group, she's so far the only character in the game who has a unique redemption arc in which Olivia (and possibly Kane) can pull her out of the darkness and she can seriously change for the better. And yes, she has a high flexibility rating too, as do Olivia, Veronica, and Dominique.
Speaking of slightly less powerful allies for GoodKaneDom, these are.
Kiyomi, however we still don't know whose side she takes. The honor code is all well and good, but I'd like some specifics...But in general, despite her profession as an assassin, you can trust her, strangely enough.
Another possible allies are Otto and Junko
(as it is already clear, both of them are highly likely to belong to the revolutionary faction). And if you play as a "pure paladin" GoodDom Kane, then, it would be a good choice..
In terms of allies among the Staff (rank S), I'd consider them more as loyal subordinates for the future Kane leader that he can always rely on than those who can help him in a real power struggle. But either way, it's, Raven (a kind and beautiful girl, in stark contrast to many sadistic JF staff), possibly Taylor and Mia.
When it comes to lower ranked allies (K - participants/slaves) who can indeed become very loyal and dedicated helpers, I would point out Angelica (K3) from our Wpod2, who has an inner moral core and is quite strong and intelligent, and her behavior so far does not raise any questions. As for Amy (K2), I would see her more as a beautiful, kind and obedient servant to rely on than as an ally.