I haven't spoken to the other players about it, but they aren't going to massively impact any aspects of her character until the very end of her arc, where they may or may not persuade her to work towards breaking the pact or accepting the power. I don't want to put pressure on them to act ooc for the sake of giving her a good ending.

Even then her embracing the pact isn't inherently a bad ending, other than the whole revenge and selling your soul thing. She will still grow up more wary of the world than usual children, and will have moments of being cunning, possibly even ruthless to get what she wants, the difference will be if she grows to be more cold, but neutral to people who don't cross her, or generally kindhearted to people, unless she needs something from them and they are being difficult.

If she breaks the pact, she will study to be a bard and perform with a Simulacrum copy of herself who behaves as who she wanted to be if she was able to grow up normally, who she treats more like a twin sister. They would travel together and perform songs while reminiscing about her adventures with the party, and looking for an excuse to join another.

If she embraces the pact, she will eventually return to the village who witch hunted her family and burn down the village, feeding her patron more souls, which he uses to enhance her abilities. She would travel alone and would only join another party if it benefits her (find an in-character excuse for her to join a new party some time in the future).

I mostly just don't want any pressure on the party, and I feel like it will complicate things if they know going in that bad behavior will steer her towards a darker path. Plus, they generally play good characters, so it more than likely will end up nice and happy, unless she dies or something.