Oh yes get herself killed without knowing whether she can gain an ally.
Grabbing the cup, testing it with silver, etc... etc... means she'll be overstepping her bounds where she can be accused of trying to kill/poison the prince herself either because she approached the prince to smash the cup out of his hands OR because they can claim she's the one who put poison in the tea if the test turns up positive (what do y'all think that little drama with the maid who ended up getting killed because she merely handed over the tea with poison in it to Castor was for then? Just for show? Lol).
If she doesn't drink it herself, instead using the methods you (and another poster) described, and nothing in her diary changes she just ends up killing herself more times unnecessarily, too.
That's exactly what y'all (including the other poster I replied to) are asking for. In what universe does that make sense?
lmao why didn't she just grabbed the tea out of his hands??