What a cute girl. I'm sure she's not bitter or resentful in the slightest.

I've been thinking about her ability a bit.
If you take "change" as being physical, it essentially refers to entropy. Her being able to prevent entropy more or less means she can stop or slow down time. It's basically Sakuya's ability done at a more integral level.
If you take "change" to be philosophical, it means she can prevent an object from altering its nature, state or identity. This would mean that the object becomes an autonomous system, so movement can occur within itself, but it cannot interact with other systems.
The way she uses her ability to hide Eientei would suggest the second interpretation is more correct, but the first interpretation is more rigorous, so both could be correct, they don't contradict each other.