Conjectural

[Sarah]

Dependent on conjecture; fancied; imagined; guessed at;undetermined; doubtful.And mak'st conjectural fears to come into me. Shak.A slight expense of conjectural analogy. Hugh Miller.Who or what such editor may be, must remain conjectural. Carlyle.

[Magaret]

based on how something seems and not on proof: