For Ashfa, as she gets closer and closer to reaching the diamonds potential, the cost of her life span to heal could get smaller and smaller. This is a more obvious one, but it does remove the reason that balancing factor is there at all, so what we do here is we add new stuff. If we keep on the healing aspect, it would be a nifty ability if she were able to spend more of her life to do something like, say, create a healing "bubble" of sorts. But that's still not all that interesting or new, so we could pull out a page from RPG land and say she could gain the ability to cast a protection on someone, not necesarily a barrier, but more like an "over heal" that would regenerate a finite and per-determined amount of injuries.
Kela can talk to animals, and at first, this doesn't seem like it could really go anywhere, but I see 2 possible routes. One could be that of shapeshifting, but doing that would be quite the process, this is a realism heavy story, but it would be possible. Alternatively, she could give her own body various features that animals already have. The eyesight of a hawk, hearing of a bat, the smell of a dog, the reflexes of a cat, the ability to see in the dark despite not being a kindred, etc. Not all at once, of course, but it wouldn't be ridiculous to say she could use the diamond to connect to animal spirits and do one of the two things mentioned.
Doing either of these things would make both of them ideal support characters for our front liners (Cojack, Belyavor, and Var).
