Mind Defense- she’s got a very unusual psychology due to the two radically different girls that made her mind. This makes it bulletproof. The Worm universe has some fairly scary mind affecting individuals.
Engineer- By default Flechette’s crossbow was a gift from another super and she doesn’t really know how it works in detail. She even switches to lower tech weapons when she stops being a Fed. This adds a minor tinker power to Lily’s cluster, focused on crossbows specifically. If it’s a crossbow, she can make it with the right materials.
MILF - Turns Flechette into a woman in her late 30s to early 40s, while also exaggerating her figure a bit. Since she’s an adult, she isn’t under the thumb of the PRT to nearly the same extent, but spending tons of time with Vista will be seen as much more sus. Tactical milf deployment.
Necromancer- Spirit calls to spirit. This will allow Rose a limited ability to call up and manipulate the spirits of the very recently killed. This will mostly be limited to asking questions and making soul pacts on Gil’s behalf. The ghosts won’t last long unless they make a deal, and will be quite weak.
Psychic- alter her ghost abilities into psionics, mainly having the benefit of making her able to do everything she could have by separating her soul from her body without leaving behind an extremely vulnerable empty shell. Remote viewing, mind control, dream reading, etc.
Succubus- Objectively speaking, what Rose has been doing with Vista is sus as fuck and morally questionable at best. Let’s make her better at it. This will give her a suite of minor master/stranger/changer powers intended to make her better at seduction.
Information Defense - Make it drastically harder to notice when Rose uses her powers, or to trace their effects back to her when they are noticed at all. Even works against information gathering superpowers and the like.